
Class Wl£M 



Book / JT-fJ 
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COPYRIGHT DEPOSIT. 






IV 



LIST OF CONTRIBUTORS. 



ANDREWS, R. R., A. M., D. D. S., F. R. M. S. ; 

BURCHARD, HENRY H. ; M. D., D.D.S. , 

CASE, CALVIN S., M. D., D. D. S. ; 

CLAPP, D WIGHT M., D.M.D.; 

CRYER, M.H., M.D., D.D.S.; 

DARBY, EDWIN T., M. D , D.D.S.; 

GODDARD, C. L., D.D.S. ; 

GUILFORD, S. H., A.M., D.D.S., Ph. D . ; 

HEAD, JOSEPH B., M. D., D.D.S.; 

JACK, LOUIS, D.D.S.; 

KIRK, EDWARD C, D D. S ; 

NOYES, FREDERICK B., B. A , D.D.S.; 

OTTOFY, LOUIS, D D. S. ; 

PEIRCE, C. N., D.D.S.; 

THOMAS, J. D., D.D. S. ; 

THOMPSON, ALTON HOWARD, D.D.S.; 

TRUMAN, JAMES, D.D.S. 



THE 



AMERICAN TEXT-BOOK 



OF 



OPERATIVE DENTISTRY. 



IN CONTRIBUTIONS BY EMINENT AUTHORITIES. 



EDITED.BY 

EDWAED (VKIKK, D.D.S., 

Professor of Clinical Dentistry in the University of Pennsylvania, Philadelphia; 
Editor of "The Dental Cosmos." 



SECOND EDITION, REVISED AND ENLARGED. 



ILLUSTRATED WITH 897 ENGRAVINGS. 




LEA BEOTHERS & CO., 

PHILADELPHIA AND NEW YORK 

1900. 








Rvfsfci 


71940 


, Ks<? 


Library oi' Congress 


^py <2. 


Two Copies Received 




NOV 7 1900 




Copyright entry 




&*v?\ ^V<^^o^ 




■JGLOJkSiA.** 




FIRST COPY. 




2nd Copy Delivered to 




ORDER DIVISION 




NOV 24 I30u 





Entered according to Act of Congress in the year 1900, by 

LEA BROTHERS & CO., 

in the Office of the Librarian of Congress, at Washington. All rights reserved. 



WESTCOTT & THOMSON, 
ELECTROTYPERS, PHILADA. 






WITH THE CONSENT OF* THE CONTRIBUTORS 



THIS BOOK IS DEDICATED TO 



JAMES TRUMAN, D.D.S., 



THE CHARACTERISTIC OF WHOSE LONG PROFESSIONAL CAREER HAS 

BEEN THE INCULCATION OF THE PRINCIPLES UPON 

WHICH THE WORK IS BASED. 



PREFACE TO THE SECOND EDITION. 



The preparation of a text-book upon Operative Dentistry, com- 
posite in its authorship, was regarded by the Editor as a tentative 
experiment the value of which could only be determined by the test 
of practical experience. The cordial reception of the work by dental 
teachers and its extensive use by students afford encouraging evidence 
that a work so planned and executed was needed. 

The increasing tendency to specialization in dentistry has rendered 
still more remote the possibility of adequately presenting the entire 
field of operative dentistry through the medium of a single volume 
of individual authorship ; hence the composite method, whereby the 
several departments are set forth by experts in each case, seems likely 
to afford the most generally satisfactory result. 

The Editor is fully aware of the importance which attaches to the 
work of harmonizing the treatment of the individual subjects and of 
so coordinating them that conflicting views shall not confront the stu- 
dent, and thus interfere with his advancement into an untrodden field; 
a recognition of this factor has served as a guiding motive both in the 
preparation and the revision of the work. 

Specialization in operative dentistry has not reached the point where 
it may be deemed best to limit the field of text-book treatment to its 
technical procedures and relegate the allied subjects to separate vol- 
umes ; hence the chapter upon Dental Embryology has been retained 
and the subject extended to include so much of Dental Histology as 
bears directly upon operative procedures, and it is anticipated that the 
admirable chapter by Professor Xoyes will prove an acceptable addi- 
tion. The chapter upon Porcelain Inlay work has been rewritten in 
the light of the most recent developments of that rapidly progressing 
field of study. The formal treatment of Asepsis and Antisepsis, which 
is the basis of an added chapter by Professor Truman, needs no 
apology; the importance of a thorough appreciation of the role played 
by oral bacteria in the causation and transmission of disease is self- 
evident, as a recognition of the bacterial factor in oral conditions has 
become a sine qua non of successful dental practice. In the present 
edition the text has been thoroughly revised, a large number of illus- 

7 



8 PREFACE TO THE SECOND EDITION. 

I 

trations and much new matter have been added, and the treatment of 
the whole subject brought into harmony with the latest development 
of thought in the field which it covers. 

The Editor desires to thank his colleagues in the educational field 
for many helpful criticisms and suggestions received since the first 
appearance of the work. These have been largely utilized in its 
revision. His thanks are also due to the several contributors for their 
generous cooperation and acquiescence in such alterations as have 
seemed desirable for the betterment of the work. 

The death of Dr. H. H. Burchard, who was so closely associated 
with this work both as a contributor and as a helpful guide in the 
preparation of the first edition for the press, creates a vacancy in the 
ranks of American dental writers which will be generally deplored, 
and especially so by his collaborators in the present work. Ill health 
made it impossible for him to take part in the present revision, 
but his contributions being based upon sound scientific principles 
needed but minor amendments, which the Editor has endeavored to 
supply in the spirit of the author. 

E. C. K. 

October, 1900. 



LIST OF CONTRIBUTORS. 



K. K. ANDREWS, A. M., D. D. S., F. B. M. S., 

Cambridge, Mass. 

HENRY H. BUBCHABD, M. D., D. D. S., 

Late Special Lecturer on Dental Pathology and Therapeutics, Philadelphia Dental 
College, Philadelphia. 

CALVIN S. CASE, M. D., D. D. S., 

Professor of Orthodontia, Chicago College of Dental Surgery, Chicago, 111. 

DWIGHT M. CLAPP, D. M. D., 

Clinical Lecturer on Operative Dentistry, Dental Department, Harvard University, 
Boston, Mass. 

M. H. CRYER, M. D., D. D. S., 

Assistant Professor of Oral Surgery in the University of Pennsylvania, Philadelphia. 

EDWIN T. DARBY, M. D., D. D. S., 

Professor of Operative Dentistry and Dental Histology in the University of Penn- 
sylvania, Philadelphia. 

C. L. GODDARD, D. D. S., 

Professor of Orthodontia, University of California, College of Dentistry, San 
Francisco, Cal. 

S. H. GUILFORD, A. M., D. D. S., Ph.D., 

Professor of Operative and Prosthetic Dentistry and Dean of the Philadelphia 
Dental College, Philadelphia. 

JOSEPH B. HEAD, D. D. S., M. D., 

Philadelphia. 

LOUIS JACK, D. D. S., 
Philadelphia. 



10 LIST OF CONTRIBUTORS. 

EDWAKD C. KIKK, D. D. S., 

Professor of Clinical Dentistry in the University of Pennsylvania, Philadelphia, 
and Dean of the Department of Dentistry. 

FREDERICK B. NOYES, B. A., D. D. S., 

Professor of Dental Histology in the Northwestern University Dental School, 
Chicago, 111. 

LOUIS OTTOFY, D. D. S., 

Professor of Clinical Therapeutics, Chicago College of Dental Surgery, Chicago ; 
formerly Dean and Professor of Dental Pathology, American College of Dental 
Surgery, Chicago, 111. 

C. N. PEIRCE, D. D. S., 

Professor of Dental Physiology, Dental Pathology, and Operative Dentistry, and 
Dean of the Pennsylvania College of Dental Surgery, Philadelphia. 

J. D. THOMAS, D. D. S., 

Lecturer on Nitrous Oxid, Department of Dentistry, University of Pennsylvania, 
Philadelphia. 

ALTON HOWARD THOMPSON, D. D. S., 

Professor of Dental Anatomy, Kansas City Dental College, Kansas City, Mo. 

JAMES TRUMAN, D. D. S., 

Professor of Dental Pathology, Therapeutics, and Materia Medica in the Uni- 
versity of Pennsylvania, Philadelphia. 



CONTENTS. 



CHAPTER I. 

PAGE 

MACROSCOPIC ANATOMY OF THE HUMAN TEETH . . . 17 

By Alton Howard Thompson, D. D. S. 



CHAPTER II. 

THE EMBRYOLOGY OF THE DENTAL TISSUES 53 

By R. R. Andrews, A. M., D. D. S., F. R. M. S. 

CHAPTER III. 

DENTAL HISTOLOGY WITH REFERENCE TO OPERATIVE DEN- 
TISTRY 93 

By Frederick B. No yes, B. A., D. D. S. 

CHAPTER IV. 

ANTISEPSIS IN DENTISTRY 157 

By James Truman, D. D. S. 

CHAPTER V. 

THE EXAMINATION OF TEETH PRELIMINARY TO OPERATION- 
METHODS, INSTRUMENTS, APPLIANCES— RECORDING RESULTS, 
ETC 173 

By Louis Jack, D. D. S. 

CHAPTER VI. 

PRELIMINARY PREPARATION OF THE TEETH— REMOVAL OF 
DEPOSITS AND CLEANING OF THE TEETH— WEDGING— OTHER 
METHODS OF SECURING SEPARATIONS— EXPOSURE OF CERVI- 
CAL MARGINS BY SLOW PRESSURE, ETC 181 



By Louis Jack, D. D. S. 



n 



12 CONTENTS. 

CHAPTER VII. 

PAGE 

PRELIMINARY PREPARATION OF CAVITIES-TREATMENT OF HY- 
PERSENSITIVE DENTIN BY SEDATIVES, OBTUNDENTS, LOCAL 
AND GENERAL ANESTHETICS— STERILIZATION, WITH A BRIEF 
CONSIDERATION OF THE PHYSIOLOGICAL AND THERAPEUTIC 
ACTION OF THE MEDICAMENTS USED 189 

By Louis Jack, D. D. S. 

CHAPTER VIII. 

PREPARATION OF CAVITIES— OPENING THE CAVITY— REMOVING 
THE DECAY- SHAPING THE CAVITY— CLASSIFICATION OF 

CAVITIES 215 

By S. H. Guilford, A. M., D. D. S., Ph. D. 

CHAPTER IX. 

EXCLUSION OF MOISTURE— EJECTION OF THE SALIVA— APPLICA- 
TION OF THE DAM IN SIMPLE CASES, AND IN SPECIAL CASES 
PRESENTING DIFFICULT COMPLICATIONS— NAPKINS AND 
OTHER METHODS FOR SECURING DRYNESS 239 

By Louis Jack, D. D. S. 

CHAPTER X. 

THE SELECTION OF FILLING MATERIALS WITH REFERENCE TO 
CHARACTER OF TOOTH STRUCTURE, VARIOUS ORAL CONDI- 
TIONS AND LOCATION, DEPTH OF CAVITY AND PROXIMITY 

OF THE PULP— CAVITY LINING, WITH ITS PURPOSES 249 

By Louis Jack, D. D. S. 

CHAPTER XL 

TREATMENT OF FILLINGS WITH RESPECT TO CONTOUR, AND THE 
RELATION OF CONTOUR TO PRESERVATION OF THE INTEG- 
RITY OF APPROXIMAL SURFACES 261 

By S. H. Guilford, A. M., D. D. S., Ph. D. 

CHAPTER XII. 

THE OPERATION OF FILLING CAVITIES WITH METALLIC FOILS 

AND THEIR SEVERAL MODIFICATIONS 267 

By Edwin T. Darby, D. D. S., M. D. 



CONTENTS. 13 

CHAPTER XIII. 

PAGE 

PLASTIC FILLING MATEEIALS— THEIE PEOPEKTIES, USES, AND 

MANIPULATION 305 

By Henry H. Burchaed, M. D., D. D. S. 

CHAPTER XIV. 

COMBINATION FILLINGS . 345 

By Dwight M. Clapp, D. M. D. 

CHAPTER XV. 

EESTOEATION OF TEETH BY CEMENTED INLAYS 369 

By Joseph Head, M. D., D. D. S. 

CHAPTER XVI. 

THE CONSEEVATIVE TREATMENT OF THE DENTAL PULP— DE- 
VITALIZATION AND EXT1EPATION OF THE PULP 401 

By Louis Jack, D. D. S. 

CHAPTER XVII. 

THE TREATMENT AND FILLING OF ROOT CANALS 429 

By Henry H. Burchard, M. D., D. D. S. 

CHAPTER XVIII. 

DENTO-ALVEOLAR ABSCESS . 479 

By Henry H. Burchard, M. D., D. D. S. 

CHAPTER XIX. 

PYORRHEA ALVEOLAEIS 505 

By C. N. Peirce, D. D. S. 

CHAPTER XX. 

DISCOLORED TEETH AND THEIE TREATMENT "535 

By Edward C. Kirk, D. D. S. 

CHAPTER XXI. 

EXTRACTION OF TEETH 561 

By M. H. Cryer, M. D., D. D. S. 



14 CONTENTS. 

CHAPTER XXI. (Continued). 

1AGE 

EXTRACTION OF TEETH UNDER NITROUS OXID ANESTHESIA . . 629 
By J. D. Thomas, D. D. S. 

CHAPTER XXI. (Concluded). 

LOCAL ANESTHETICS AND TOOTH EXTRACTION 639 

By Henry H. Buechaed, M. D., D. D. S. 

CHAPTER XXII. 

PLANTATION OF TEETH 645 

By Louis Ottofy, D. D. S. 

CHAPTER XXIII. 

MANAGEMENT OF THE DECIDUOUS TEETH 663 

By Clark L. Goddard, A. M., D. D. S. 

CHAPTER XXIV. 

ORTHODONTIA EXCLUSIVELY AS AN OPERATIVE PROCEDURE . . 683 
By Clark L. Goddard, A. M., D. D. S. 

CHAPTER XXV. 

THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS 805 

By Calvin S. Case, M. D., D. D. S. 

INDEX 843 



INTRODUCTORY. 



A study of the advances which have of recent years taken place in 
the field of Operative Dentistry will reveal, besides the important addi- 
tions to our knowledge in the shape of novel methods and improved 
technique, a vastly more important advance manifested in a better and 
more general understanding of scientific principles, and the application 
of dental science to dental art, resulting in a more rational practice. 
Especially is this true in regard to the etiology of dental and oral 
pathological conditions, and the rationale of the modes of treatment 
indicated for the morbid states constantly confronting the dental 
practitioner. 

The modifications in surgical methods and the greatly improved 
results which are the outgrowth of modern scientific studies in bacterial 
pathology, while they have made a considerable impress upon dental 
operative methods, have not, however, received that universal practical 
acceptance among dental operators which their immense importance 
demands. There is no field of special surgery in which the import- 
ance of exact knowledge with respect to aseptic and antiseptic treat- 
ment is more marked than in the practice of dentistry. The dental 
operator is continually confronted Avith septic conditions, so that pre- 
cise knowledge of their origin, causes, phenomena, and treatment are 
essentials to the legitimate practice of the profession. 

The performance of any operation, and especially those which are 
classified as capital, with unclean hands or infected instruments would 
in the present stage of surgical art be regarded as criminal malpractice. 
It should be so considered in dentistry. The loss of a patient's life as 
the result of surgical septic infection is no longer permissible. Lack 
of antiseptic precautions in certain dental operations may directly lead 
to and as a matter of fact has been the cause of fatal results. It has 
been shown conclusively ] that a large variety of pathogenic micro- 
organisms are almost constant inhabitants of the oral cavity. In addi- 
tion to the numerous forms which bring about an acid reaction, there 
are many specified organisms which produce in inoculated animals 
pyemia and septicemia in their several clinical classes. But while the 
dental practitioner is not often called upon to face the issues of life 



15 



1 6 INTR OD UCTOR Y. 

and death in the course of his work, his responsibilities as related to 
the issues with which he does deal demand of him the same care and 
thoroughness in order to attain the character of result which the pos- 
sibilities of modern dentistry require of him. In the following pages 
the importance of asepsis and antisepsis in dental operations is con- 
stantly impressed upon the mind of the student. 

By the term asepsis is specifically meant the condition under which 
are excluded those influences or causes which induce infection by patho- 
genic micro-organisms ; when a tissue or surface has been rendered 
germ-free it is said to be in an aseptic condition. By antisepsis is 
meant the means by which the septic state is combated or the aseptic 
state is attained. 

Under the aseptic condition repair of tissues takes place normally 
without interference, wounds and injuries heal with a minimum of dis- 
turbance, and the inflammatory concomitant is of the simple traumatic 
type, without suppuration or tendency to diffusion . 

The aseptic state, in many operations in the mouth, is not readily 
attainable and cannot be maintained for any length of time ; but in all 
operations which involve the pulp and pulp chamber, as well as the 
periapical region through the pulp canals of teeth, strict aseptic con- 
ditions, as regards external infection, are perfectly attainable through 
exclusion of the oral secretions by means of rubber dam, the use of 
suitable disinfectants, and sterilized instruments. It is the class of 
operations here alluded to which are most prolific of disturbance from 
infective inflammations caused by ignorant or careless manipulation. 

The time is at hand, if indeed it has not already arrived, when puru- 
lent inflammations following dental treatment will be regarded with 
the same condemnation of the dentist as of the general surgeon. The 
operative section of this work is written in full recognition of the prin- 
ciples here indicated. 



OPERATIVE DENTISTRY. 



CHAPTER I. 

MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

By Alton Howard Thompson, D.D.S. 



1. Definition. — The teeth may be properly defined as hard, cal- 
careous bodies situated in that portion of the alimentary canal near the 
anterior or oral extremity. In man they are confined to the oral cavity 
and are supported by the maxillary bones only. In the lower verte- 
brates they may be scattered over all of the bones and cartilages sur- 
rounding the mouth. 

2. Function. — The main function of the teeth is the mechanical sub- 
division of substances used for food, preparatory to their digestion ; these 
organs therefore belong to the alimentary system. The elements of 
their function are prehension, incising, crushing, mastication, and insali- 
vation. For the performance of these various offices, different forms 
of teeth are found in the denture of man. In lower animals food-habit 
induces the evolution of many various and extreme forms of the teeth. 

The secondary offices of the teeth in man are as adjuncts in vocal- 
ization and articulate speech ; they also bear an esthetic relation to the 
mouth and face. 

Fig. 1. 
a b c d e 






The formation of single teeth from the single cone and its repetition in complex teeth. 

3. Mechanical Design. — All tooth forms are evolved by modification 
from a simple cone, which is the primitive, typal form. The teeth of fishes 
and reptiles are but simple cones, and those of higher mammals are 
modifications of the single cone or combinations of two or more cones 

2 17 



18 MACROSCOPIC ANATOMY OF THE HUMAN TEETH 

fused together. Thus in man the incisors are formed of a single cone, the 
truncated apex of which is compressed to form the wide cutting edge (Fig. 
1, a). The canine or cuspid is a single cone, the apex of which is com- 
pressed into a trihedral point, or pointed pyramid (b). The bicuspids 
are composed of two cones fused together, the forms of the cones being 
quite distinct the entire length of the tooth, as in the upper bicuspids (c). 
The typal upper molar is formed by the addition of the third cone to 
the bicuspid form, as plainly noticed in the three roots and the primitive 
three cusps (d). The usual quadricuspid form is made by the addition 
of a cingule. The lower molar consists of four cones, which may be 
plainly distinguished by an analysis of its elements (e). Each cone in 
the structure of a tooth is surmounted by a cusp or tubercle. Extra cusps 
above the number of primary cones are but cingules or undeveloped cusps. 

In the genesis of tooth forms, therefore, the complex teeth, as the 
bicuspids and molars, are formed by the repetition and addition of cones 
and their accompanying cusps, both laterally and longitudinally of the jaw. 

4. The Dental Arch.— The teeth of man are arranged around the 
margins of the upper and lower jaws in close contact, and have no 

Fig. 2. 




Square. Rounded Square. Rounded. Rounded v. 

The main types of the dental arch. 

interspaces between them. The basal arch is a graceful parabolic curve, 
with some variations which lead from the round arch to the incomplete 
parallelogram or even to a well-defined V shape. These variations may 
be classified as follows : 

First : The square arch (Fig. 2, a). This is found usually in 
persons of strong osseous organization, of Scotch or Irish descent — i. e. 
of Gaelic extraction — and is probably derived in the first instance from 
a dolichocephalic people. The squareness is more or less dependent 
upon the prominence of the large canines, which stand out very 
markedly at the angles of the square. The incisors present a flat front 
and project slightly, with little or no curve of the incisive line. 
The bicuspids and molars fall backward from the canines with no per- 
ceptible curve. The two sides are quite parallel, but sometimes there 
may be a slight divergence toward the cheek at the rear. This is the 
low form of arch which appears in the apes and some low races. 



THE OCCLUSION OF THE TEETH. 



19 



Second : The rounded square (Fig. 2, b). This is the medium 
arch and is the form usually met with in ordinary , well-developed ro- 
bust Americans. The canines seem to be only so prominent as to give 
character to the arch without a resemblance to the arches of the lower 
animals. The incisors are vertical and the line curves slightly from 
one canine to the other. The bicuspid-and-molar line curves slightly 
outward from the canine and converges at the rear. 

Third : The rounded arch (Fig. 2, c). This is the circular or 
"horse-shoe" arch. It is nearly semicircular, the ends curving in- 
ward at the rear, the outlines of the arch tracing a decided horse-shoe 
shape. The canines are reduced to the level of the arch, so that there 
is no prominence of these teeth. The bicuspids and molars follow the 
line of the curve. This arch is quite characteristic in some races, as 
the brachycephalic South Germans. 

Fourth : The rounded V (Fig. 2, d). In this form the round arch is 
constricted in front or narrowed so that the incisors mark a small curve 
whose apex is the centre. It is the arch of beauty and is that most 
admired in women of the Latin races. 

These are but the basal forms of the dental arch. Ordinarily, mod- 
ifications of these types occur in all degrees ; it is the variations, the 
composites, which are most met with. 

5. The Occlusion of the Teeth. — The upper teeth describe the seg- 
ment of a circle larger than that of the lower teeth ; so that the edges 
of the anterior teeth above close over those below, and the buccal cusps 
of the grinding teeth above close outside of the buccal cusps of the 
lower teeth (Fig. 3). By this arrangement the buccal cusps of the 
lower grinders are received into the de- 
pressions or sulci between the buccal and 
lingual rows of the cusps and tubercles 
of the superior molars and bicuspids, and 
the lingual cusps of the upper grinders 
are received into the sulci of the lower 
grinders. By this arrangement the whole 
of the morsal surfaces of these teeth are 
brought into contact in the several move- 
ments of mastication, thereby rendering 
the performance of this function more 
effective. 

Then, again, the upper incisors usually 
close over the lower for one-third of their 
length. This allows of the shearing action by which the incisive func- 
tion is performed as the edges of these teeth are drawn past each other. 

The line of the horizon of occlusion (Fig. 4, A-B) presents a decided 



Incisors, 



Fig. 3. 
Bicuspids 



Molars. 




The relative position of the upper 
and lower teeth in occlusion. 



20 



MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 



curve from front to rear, of greater or less degree in different forms of 
the arch. Thus it is high at the incisors, curving downward at the bicus- 
pids, reaching its lowest point at the first molar ; it curves upward rap- 
idly at the second molar, and is highest, again, at the third. In the 
rounded arch the plane is more flattened, and it exhibits the extreme 

Fig. 4. 




The horizon of the line of occlusion and plane of occlusion. 

downward curve in the square arch. Between these extremes there 
is of course every variety of modification. The form of the plane of 
occlusion is shown in Fig. 4, C. 

Fig. 5. 




The apposition of the upper and lower teeth. 



The tendency of the bolus of food is toward the lowest part of the 
curve at the region of the lower first molar, so that the extraction of 
this tooth always affects the performance of mastication. 

In the apposition of the teeth of the opposite jaws the mechanical 



THE OCCLUSION OF THE TEETH 



21 



arrangement is such that the dynamics of mastication is subserved 
and the greatest effectiveness secured (Fig. 5). Thus the morsal sur- 
face of the upper central incisor is opposed to all of that of the cen- 
tral incisor below and to the mesial half of the lateral ; the upper lat- 
eral opposes the distal half of the lateral below and the mesial face of 
the canine ; the upper canine, the distal half of the face of the lower 
canine and the mesial half of the first bicuspid ; the upper first bicuspid 
opposes the distal half of the lower first bicuspid and the mesial half 
of the second ; the upper second bicuspid opposes the distal half of 
the lower second bicuspid and part of the lower first molar : the upper 
first molar opposes the distal part of the lower first molar and the me- 
sial half of the second ; the upper second molar opposes the distal half 
of the lower second and part of the third ; and the upper third covers 
the remainder of the lower third molar. 

By this method of apposition the teeth are so arranged that two 
teeth receive the impact of half of two of the opposite jaw, thus 
distributing the force of occlusion and ensuring the safety and strength 
of the teeth. This " break-joint " arrangement permits each tooth to 
bear two opposing ones, and also helps to preserve the alignment. 

Fig. 6. 




Incisors. Canines or Premolars or Molars, 

cuspids. Bicuspids. 

The classes of the teeth, comprising the left half of a full denture. 



Then again, if one tooth be lost, the opposing teeth still rest against 
two teeth, one at each side of the space. The normal condition of 
the articulation is rarely preserved, however, as mutilation usually dis- 
turbs it ; the teeth move on account of the force of occlusion, and effec- 
tive mastication is more or less destroyed. 



22 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

6. Number and Classes of the Teeth. — Man has thirty-two teeth, 
divided into four classes, viz. — (1st) incisors, (2d) canines or cuspids, 
(3d) premolars or bicuspids, and (4th) molars (Fig. 6). This is 
expressed by the dental formula as follows : 

. 2—2 1—1 ,. 2-2 3—3 

^. , c. , bi. , m. = 32. 

2-2' 1 — V 2—2' 3—3 

(1) The incisors are eight in number, four above and four below, — 
two on each side of the median line. The two next to the median line 
are called the central incisors, the ones next to them distally, the lat- 
eral incisors. 

(2) The canines are four in number, two above and two below, — 
one on each side immediately approximating the lateral incisor on the 
distal side. 

(3) The bicuspids are eight in number, four above and four below, 
— two on each side approximating the canines on the distal side. 
The first of these next the canine is called the first bicuspid, the one 
next to it on the distal side the second bicuspid. The same designa- 
tion applies to both upper and lower bicuspids. 

(4) The molars are twelve in number, three on each side of each 
jaw, approximating the second bicuspid on the distal side. The 
molar next to the second bicuspid, both above and below, is called the 
first molar ; the next one distally is called the second molar ; the next 
one distally, and the last tooth in the jaw, is called the third molar or 
" wisdom tooth " (dens sapientice). 

Functionally, the incisors are formed for cutting, as their name im- 
plies ; the canines for prehension and tearing (for which purpose this 
tooth in lower animal forms is often excessively developed). It also 
serves in guiding the bite. The bicuspids are the crushing teeth, and 
the molars are formed for grinding, triturating and insalivating the 
food. 

The Incisors. 

7. The Upper Central Incisor. — This is the first tooth in the den- 
tal series in man. It is situated in the front of the mouth, next to the 
centre of the arch, which is the mesial border of the intermaxillary 
bone. In adult man these bones fuse with the anterior borders of the 
right and left superior maxillary bones. Their junction with each other 
marks the centre of the dental arch. 

The general form is that of a truncated cone with its top flattened 
out to form the cutting edge. 

Its function is to cut or incise food, hence its name from the Lat. 
incisus, 



THE INCISORS. 



23 



The mechanical structure of the crown is a matter of importance. It 
will be observed that it consists of several elements : first, a broad cut- 
ting blade (Fig. 7, a) supported by two strong lateral columns (6) on 

each side, and that these columns 
are upheld by two strong marginal 




The mechanical design of the crown of 
the upper central incisor : a, the blade ; b, 
the two columns supporting the blade ; c, 
the marginal ridges acting as guys, brac- 
ing the columns ; d, the basal ridge as the 
base of attachment for the guys. 




d f 

Diagram of the labial face of the upper central 
incisor. 



ridges (c) leading up from the lower ridge (cl). These ridges are but- 
tresses, which guy and uphold the columns which contain and carry the 
blade. Hence, when these ridges are destroyed by caries or in operating, 
the support of the column is lost and the blade readily breaks away. 

The form of the crown is spade-like, or a compressed-wedge shape, 
the edge being quite thin and the thickness increasing rapidly to the 
base. It is slightly bent toward the lingual side, or much curled over in 
some cases. 

The labial face is imperfectly square or oblong, the cervical margin 
being rounded (Fig. 8, a). It is convex from side to side, but only 
slightly so from cervix to edge. Two shallow depressions or furrows 
extend the length of the face perpendicularly (6) dividing it into 
thirds, called lobes, — the mesial, (c), median (cl) 
and distal lobes (e). These furrows and lobes are 
quite conspicuous when the tooth is erupted, but 
are abraded by age and the wear of use and denti- 
frices, until the face becomes smooth. The mesial 
margin is a little longer than the distal so that 
the cutting edge slopes upward toward the distal 
side (/). ^ 

The lingual face is smaller than the labial, 
being on the inner and smaller curve of the 
crown, and is narrower from side to side (Fig. 9). 
It is triangular in outline, being wide at the edge and narrow and 
rounded at the base or cervix. The marginal ridges (a) are high 
and conspicuous, and extend from the basal ridge to the edge on the 




Diagram of the lingual face 
of the upper central in- 
cisor. 



24 



MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 




Mesial. Distal. 
The mesial and distal faces and 
edge of the upper central in- 
cisor. 



mesial and distal margins of this surface. The basal ridge (6) is a 
strong elevation continuous with the marginal ridges at the base of 
the crown. It is sometimes developed into a raised cusp, the ridge 
at the base of which forms a cingulum. A ridge or lobe (c) extends 
from the basal ridge to the centre of the edge, uniting with the median 
lobe from the labial face to form the median tubercle. A depression 
or fossa (d) is found on each side of the median lobe between it and the 
marginal ridges, or, when the lobe is low or entirely absent, these fossae 
may be continuous. A fault or fissure at its junction with the basal 
ridge forms the seat of caries in teeth of low structure. 

The mesial face (Fig. 10) is a rather long triangle in shape, with a 
concaved base at the cervix of the tooth (a), 
and a long point toward the edge. It is 
nearly straight in a longitudinal direction, 
but rounded and convex transversely. It is 
longer than the distal face, the edge descend- 
ing in that direction. The enamel line dips 
downward into this face, and there is a de- 
pression above it (b) which sometimes extends 
upward on the root. The point of contact 
with the opposing tooth is near the cutting 
edge. 
The distal face is also triangular in outline (Fig. 10) but it is more 
curved in the longitudinal axis, so that this surface is convex in all 
directions. It is most curved in the transverse direction. The enamel 
dips downward into the surface (d), as in the mesial, but there is not so 
much of a depression above this line. The point of contact is one-third 
of the distance from the angle (<?). 

The edge, or morsal margin, of the crown is formed by the com- 
pression of the top of the truncated primitive cone. It is quite wide 
and square except at the distal corner, which is rounded. The angle 
with the mesial face is acute (Fig. 10, /). When the tooth is first 
erupted, the edge has three prominent tubercles (g), which correspond 
to the ridges on the labial and lingual faces. These are soon worn off 
with use, so that the edge usually looks straight. The pitch of the 
edge is toward the median line. 

The neck of the central incisor is a rounded pear-shape in outline, 
the labial half being wider (Fig. 11, a) than the lingual. There is not 
much constriction of the tooth at the neck. The enamel edge curves 
upward on the root on the labial and lingual sides, and dips down- 
ward on the mesial and distal faces. It terminates abruptly on all 
sides, especially on the lingual, where a considerable ridge is some- 
times raised (Fig. 10, c). 



THE INCISORS. 



25 



Fig. 11. 




The root of the upper cen- 
tral incisor. 



The root is cone-shaped and tapering (Fig. 11, b). The rounded 
pear-shaped section continues almost to the end. 

The pulp chamber is spacious and open, and of 
the general form of the tooth (a and c). The radi- 
cal portion of the canal gives free access, but the 
flattened coronal portion is difficult to cleanse. In 
young teeth the cornua or horns of the pulp may 
project far toward the angles (c). 

8. The Lateral Incisor. — This tooth approxi- 
mates the central incisor on its distal side, and is 
also implanted in the intermaxillary bone. It is 
of similar spade-like form and of the same architectural design as the 
central, modified by the distal half being more rounded in every direc- 
tion. As the crown is narrower than the central, the destruction of the 
marginal ridges on the lingual face weakens the edge still more, so 
that it breaks off more easily. The crown is narrower in the rnesio- 
distal diameter than the central, but, still almost as w T ide labio-lingually, 
the relative difference of thickness in the two directions is more ap- 
parent. The tooth has the appearance of being compressed mesio- 
distally. The thickness increases rapidly from the edge to the neck 
(Fig. 12, B). 

Fig. 12. 




The upper lateral incisor. 



The labial face (Fig. 12, C) is more rounded than that of the cen- 
tral. It is half incisor and half canine (a), the mesial half toward the 
central incisor resembling that tooth (6), and the distal half toward 
the canine resembling it (c). The mesial angle of the edge is quite 
acute, while the distal angle is rounded and obtuse. The three lobes 
may be well developed, similar to those on the central incisor, but 
are usually indistinct, although the central ridge is prominent. 

The lingual face (Fig. 12, D) is much depressed, but less concave 
than that of the central incisor. The marginal (d) and basal ridges (e) 
are quite prominent. The basal ridge is often raised into a prominent 
cingule or talon, an exaggerated example of which is shown in Fig. 
13, which is a revival of the basal talon found in the apes, — and 
the insectivora. This cingule occurs more frequently on the lateral 




a 



26 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

incisor than on any other of the anterior teeth. The depression 
above it is often the location of a fault, a fissure or pit, which be- 
comes the seat of caries. The basal ridge is 
sometimes cut by a fissure which leads down quite 
upon the neck of the tooth (Fig. 12,/). 

Sometimes the entire surface is full and rounded 
without any concavity whatever. 

The mesial face (g) is of triangular form similar 

a to that of the central incisor. It is rounded toward 

the edge labio-lingually, but flattened at the neck, 

with a depression at the enamel line which leads 

Showing unusual develop- . . 

ment of the cinguie or upward upon the root. The labial angle is some- 

basal talon on an incisor. timeg ^ geat f a depression (h), which gives the 

(From case reported by Dr. r \ /? 

w. h. Mitchell, nentai Cos- angle a hook shape. The depression varies in 
mo*, vo . xxxi-v . p. 1036.) w j^th and depth and may become the seat of 
caries. The point of contact with the central incisor is at the junction 
of the lower with the middle third of the length of the face. 

The distal face is more convex in all directions and resembles the 
canine in form, being in harmony with the general form of the distal 
half of that tooth. From cervix to edge it is rounded and the contact 
eminence in the middle third is very full (i). From this point it rounds 
off rapidly to the edge. The upper third is depressed rapidly toward 
the cervix, with a considerable depression at the enamel line leading 
off to the distal groove on the root. 

The edge is divided into two portions by the prominent tubercle (j) 
in the middle which terminates the prominent central ridge of the 
labial face. The mesial half is straight, like that of the central. 
When worn, these features disappear and the edge becomes almost 
straight. The pitch of the edge, like that of the central, is toward 
the median line. 

The neck is much flattened mesio-distally, and is of a compressed 
pear shape, or flattened oval on section. The enamel margin pursues 
the same course as on the central incisor, rounding upward toward the 
root on the labial and lingual sides and dipping downward on the 
distal and mesial. It does not terminate sO abruptly as that of the 
central incisor, and presents less of a ridge at the gingival margin. 

The root is commonly longer than that of the central incisor, is 
narrower, flattened mesio-distally (Fig. 12, .1, B). It tapers gradually, 
not rapidly like the root of the central incisor. It is a flattened oval 
on section (e). Sometimes there is a hook at the end, curved distally. 
Grooves sometimes occur on the mesial and distal sides. 

The pulp canal is flattened in conformity to the shape of the root, 
but is readily entered if the root be straight. 



THE INCISORS. 



27 



The lateral incisor is very irregular as to form, presenting various 
degrees of deformity or abnormality, and may sometimes be reduced to 
a mere peg. It is also erratic as to eruption, being sometimes sup- 
pressed, not appearing for several generations of a family. It follows 
the third molar in the frequency of its irregularities both as to form 
and frequency of non-eruption. 

The third incisor of the primitive typal mammal sometimes reap- 
pears in man, and is known as a supernumerary. It rarely assumes the 
proper incisor form and position in the arch, but usually erupts within 
the arch and is a mere pointed-peg-shaped tooth. 

9. The Lower Incisors. — These are most conveniently described as 
a group, as they are very similar in form, having but slight variations 
between the central and lateral incisors to be noted. 

They are located in the anterior portion of the lower jaw, upon each 
side of the median line, opposite the incisors above. Their function is the 
same as that of the upper incisors, the cutting of food, which they per- 
form by opposing the upper. The lower central opposes only the cen- 
tral above ; the lateral, both the upper central and lateral incisors. 

The lower central incisor is the smallest tooth in the dental series. 
It is of spade-like form (Fig. 14), the crown being a double wedge 
shape (a, b). The first wedge (a) is observed on viewing the crown 
from the front, the widest portion being 
at the morsal edge and the point at the 
cervix. The second wedge is observed 
from the side (b), the widest part being 
at the neck and the point at the morsal 
edge of the crown. The edge is thin, 
but the labio-lingual diameter increases 
rapidly to the cervix, which is the 
widest part. The crown is widest 
mesio-distally at the edge, but diminishes to the neck, which is scarcely 
more than half the width of the edge. The tooth cone is therefore 
compressed in one direction at the edge, and in another at the cervix. 
The mechanical elements are the same as those of the upper central, but 
with the parts less strongly marked. 

The labial face is a long wedge shape (a), the widest part at the 
edge and narrowing to the cervix. It is usually straight, or nearly 
so, longitudinally, and straight across the edge, but round and con- 
vex at the neck and the cervical half. Sometimes vertical ridges are 
found on these teeth when they are first eruptedy but these soon 
wear off. 

The Ungual face is depressed and concave from edge to cervix (c), 
but less so from side to side. The marginal ridges are often well 




The lower incisor. 



28 MACROSCOPIC ANATOMY OF THE HUMAN TEETH 

marked. In the lateral incisor the fossa is often more marked and 
the marginal ridges more distinct. 

The mesial and distal sides are of wedge-like form, straight from edge 
to cervix and widening in the same direction. A depression runs across 
the neck just above the enamel line. 

The neck is much compressed disto-mesially, and the root partakes 
of this flattening through its entire length. The section presents a 
compressed oval (e). The enamel line dips downward on the labial and 
lingual sides, and curves upward on the mesial and distal, in a manner 
characteristic of the incisors. 

The edge is perfectly straight from side to side, after the three tuber- 
cles, found when first erupted, are worn off. 

The root is flattened like the neck, and frequently a groove runs the 
entire length on the mesial and distal sides. Occasionally complete 
bifurcation results, which recalls the form of this tooth found in lower 
animals. 

The pulp canal (e) is of similar form to the root, and is flattened 
and thin, so that it is often difficult to effect an entrance to it with 
instruments. 

The lateral is similar in form to the central incisor, but is wider at 
the edge and the distal corner of the edge is slightly rounded (d). In all 
other features it resembles the central incisor. 



The Canines or Cuspids. 

10. The Upper Canine. — This is the third tooth from the median 
line and approximates the lateral incisor on its distal side. It is the 
first tooth posterior to the intermaxillary suture and is imbedded in 
the maxilla proper. It is commonly said to form the spring of the 
arch, and conveys the impression of great strength, as is indicated by 
its strong implantation. It is more strongly implanted, and by a longer 
and larger root, than any of the other teeth. Zoologically it is the 
largest tooth in the dental series, but in man is much reduced from 
its prototype, the larger carnassial canine of lower animals, especially 
the carnivora. It is the principal prehensile tooth, and is therefore 
first in order of function in the dental series. 

The canine in man preserves the typal form, for its mechanical 
structure is still that of a single cone, brought to a point (Fig. 
15, a). This is the earliest form of teeth found in the lower verte- 
brates, the fishes and reptiles, which present only simple conical teeth 
in all parts of the jaw. It has an older history than any other tooth, 
and still bears the marks of the many changes through which it has 
passed in the course of its evolution. 



THE CANINES OR CUSPIDS. 



29 



The crown has a spear-head shape (6), hence the name, cuspid, by 
which this tooth is frequently designated, from the Lat. cuspis, " point, 
pointed end." It is constructed essentially for piercing and tearing. 
The central cusp or point is braced in all directions ; the edges leading 
up to it both mesially and distal ly (which serve for cutting as well), the 

Fig. 15. 




c d e 

The upper canine. 



strong labial ridge coming downward from the cervix (c) to the median 
ridge leading up on the lingual surface (d), all support it in the office 
of prehension and the laceration of flesh. 

The labial face (b) presents the outlines of the spear shape, more or 
less rounded in different cases. Starting from the well-defined cusp just 
in front of the central axis of the tooth, it widens sharply for about 
one-third of its length, whence it narrows gradually to the gum line, 
which is fully rounded. In some cases the mesial and distal angles are 
rounded and the outlines are more of a leaf shape (e). The surface 
is slightly rounded mesio-distally, so that the sides slope roundly or 
flatlv away from the central ridge. This ridge descends from the middle 
of the cervical margin, curving slightly forward and then backward to 
the point of the cusp (c). This curve recalls the curving shape of this 
tooth in the Felidse. It is usually a sharp, prominent ridge, but may 
be reduced and rounded so as to be scarcely perceptible. The three lobes 
of the surface are imperfectly marked, — the central ridge dominating 
and dwarfing the lateral ones. The lateral furrows on each side of 
the central ridge separating it from the lateral lobes are more or less 
marked, especially toward the edge. Wear reduces in time the prom- 
inence of the lobes and ridges and obliterates the furrows. 

The lingual face is of similar spear shape (d), but is more flat. It is 
rarely concave. The thickness of the crown increases gradually to 
the lateral prominences, which gives a blade-like edge, then rapidly 
to the shoulder at the base. A strong vertical ridge extends from the 
cusp to the basal ridge (d), with a slight concave depression on each 
side. The basal ridge is well marked and sometimes develops into 
a cingule, more or less marked. The marginal ridges lead up on each 



30 MACROSCOPIC ANATOMY OF THE HUMAN TEETH 

side only so far as the lateral protuberances. They are not strongly 
marked as a rule. The fossae on each side of the vertical median ridge, 
between it and the marginal ridges, may be quite deep but are usually 
shallow and ill defined. 

The mesial face in outline is not unlike the central incisor, but its 
contour is very different, for it is more or less rounded in all direc- 
tions, and the lateral eminence in the lesser third makes this part espe- 
cially full (i). From this point the surface is depressed roundly to the 
enamel line at the neck, where a depression of greater or less depth is 
found. It is somewhat flattened at the cervix. The point of contact 
is at the eminence, which touches the lateral incisor. 

The distal face is of similar form to the mesial, except that it is more 
full and the eminence more pronounced, which gives the increased width 
of the crown on that side. The surface descends rapidly toward the neck 
and is rounded labio-lingually. The point of contact with the first bi- 
cuspid is on the lateral protuberance. 

The morsal edge presents a prominent cusp which is almost central 
to the long axis of the tooth. The side facets slope away, but still retain 
their cutting edge (6). The distal side of the edge is longer than the 
mesial, by reason of the increased size of the distal protuberant angle. 
The sharp point is soon worn off to a rounded cusp, and, as wear 
increases with age, it may be reduced to a straight surface between the 
mesial and distal protuberances (g). 

The neck is a flattened oval on section, or the lateral direction of the 
labial portion may be greater than that of the lingual (A). The enamel 
line preserves the same curves as on the incisors, i. e. rounding upward 
on the labial and lingual surfaces and dipping downward on the mesial 
and distal. The enamel terminates gradually with but a slight ridge, 
unless it should be on the lingual side. A depression occurs on both 
mesial and distal sides above the curve, which may lead up as a groove 
on the root. 

The root is longer than that of any other tooth, and it is at least 
one-third larger than that of the central incisor. It is of a rounded 
trihedral form, or irregularly conical. It is usually straight, and tapers 
to a slender point, which may be curved or very crooked. In well- 
arranged dentures, where it has erupted naturally, it is usually straight. 

The pulp canal is large and open, of the same form as the tooth, and 
easily entered. It is regularly formed except in those cases where the 
root is curved, and even in these it can be filled if not too crooked, as 
it is so open and accessible. 

11. The Lower Canine. — This is similar to the upper in form and 
outline, except that it is somewhat smaller, more slender, and more 
rounded in form (Fig. 16, a). It differs also in being more compressed 



THE CANINES OR CUSPIDS. 



31 



mesio-distally and in being flattened in the neck and root, The crown 
leans backward on the root so that the mesial face is almost straight the 
entire length of root and crown. It forms the spring of the lower arch, 
and is strongly built to oppose the strong upper canine in the act of 
prehension and tearing. It opposes the mesial surface of the canine 
above and the distal surface of the upper lateral incisor. 




/> c 

The lower canine. 



The labial face is a long oval (a), the cusp being blunt and the neck 
rounded while the mesial side (c) is flattened. The lobes are indistinct 
and the central ridge rounded from side to side. The entire face is in- 
clined inward to accommodate the occlusion. The crown in many cases 
presents the appearance of being blunt toward the distal side. 

The Ungual face (b) is flat, sometimes cup-shaped, and the marginal 
ridges are not prominent, The central ridge sometimes stands out 
strongly. The basal ridge is weak and is rarely developed into a 
cingule. The crown increases gradually in thickness from the point 
to the neck. 

The morsal surface presents a mere rounded eminence ; the cusp may 
be sharp in childhood, but usually it is soon reduced by wear. Some- 
times it remains sharp and prominent, The lateral edges are not devel- 
oped, but are mere ridges leading down to the lateral faces, which are 
not prominent, except the distal (d), which is often full. 

The mesial face is quite flat, and straight with that face of the root. 
The eminence is not marked. It is rounded only at the eminence, but 
flattened at the cervical third (c). 

The distal face has the most prominent eminence (d), the crown being 
bent in that direction. The cervical third of this face is flat. It descends 
rapidly from the eminence. 

The neck is usually oval (/) or, when compressed, spindle-shaped 
upon section (g), being depressed on the mesial and distal sides at the 
origin of the grooves running up on the root, The enamel line is 
not so variable as on the incisor, but more nearly on a level on all four 
aspects. 



32 



MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 



The root is long, flattened, and tapering («, 6, c). It is shorter than 
that of the upper canine. It is grooved on the mesial and distal sides, — 
so much so as to tend toward bifurcation. This, indeed, sometimes hap- 
pens in man, thereby recalling the form usual to the primates and some 
other lower animals. 

The pulp canal is of the same general form as the root, often pre- 
senting the spindle shape on section. It is somewhat difficult to enter 
on account of its flattened shape and narrowed channel. 



Fig 




b c 

The upper bicuspids 



ment of a root to support it. 



The Bicuspids. 

12. The Upper Bicuspids. — The upper bicuspid is formed by duplica- 
tion of the primitive cone and cusp in a transverse direction (Fig. 17, a). 

Viewed from the standpoint of com- 
parative dental anatomy, the external 
cone is the canine cone — and to this is 
added the internal or bicuspid cone, the 
tooth being a double canine. The bi- 
cuspids are the first of the complex 
teeth. The internal cusp is formed 
by the raising of the inner primitive 
cusp of the canine and the develop- 
The distinctive feature of the architec- 
ture, therefore, is its formation from two cones, and this makes it a 
weak tooth as regards its mechanical structure and resistance to mas- 
tication, for the binding of the bases of the cones and cusps depends 
upon the connecting power of the two marginal ridges (b, b), and when 
these are destroyed the cones readily part and split off. 

The bicuspids in man are homologous with the premolars of the 
quadrumana and other lower mammals. They succeed and displace the 
molars or grinders of the deciduous set. They are placed next after the 
canines in both jaws, and midway between the cutting and grinding teeth. 
Their function is the crushing of food preparatory to mastication. 

The upper first bicuspid approximates the canine on the distal side. 
The buccal face (c) is of spear-head shape, similar to that of the 
canine. This is more apparent in some lower mammals than in man, in 
whom it is much reduced and rounded, so as to give usually the appear- 
ance of a long, rounded oval. The buccal cusp (c) rises sharply and 
prominently from the lower centre of the face, from which a strong ridge 
(d) leads up to the cervical border. The mesial and distal lobes (e, e) are 
rarely conspicuous, and the furrows between them and the central ridge 
lead but half way up the crown. The lobes sometimes have prominent 
points at the morsal margins which in lower mammals become pro- 




THE BICUSPIDS. 33 

nounced cingules. The buccal marginal ridges descend from the 
points of the cusp to the points of the lateral lobes. The distal ridge 
is usually longer than the mesial. The cervical border is rounded and 
oval from side to side. 

The lingual face (f) is full and rounded, more or less straight perpen- 
dicularly and rounded mesio-distally. It is convex in both directions. 
The lingual cusp rises over it full, but is blunt and round ; the mar- 
ginal ridges are rounded, not angular, and curve sharply round to meet 
the mesial and distal marginal ridges. 

The mesial face (Fig. 18, g) is wide and flat transversely, full at 
the morsal surface at the marginal ridge, which is prominent, and de- 
scending flat to the cervix, where 
a depression (h) occurs which ex- 
tends well up the face. 

The distal face is of similar 
form, but is rather more convex 
and the portion at the marginal 
ridge more prominent. The de- 
pression from the root does not 
extend so far up on the face. The upper bicuspids. 

The morsal surface shows an 
abrupt change from that of the canine next to it, as it presents two 
distinct cusps or points instead of one. One cusp is on the buccal 
margin (j) of the crown, and one on the lingual (&), and they are named 
the buccal and lingual cusps. The buccal cusp is sharp and prominent, 
and is not unlike the single canine cusp. The lingual cusp is broader 
and more rounded — indeed it is preferable to term it a tubercle. 

The outline of the morsal surface is imperfectly quadrate and is bor- 
dered by well-marked marginal ridges, named as follows : 

The mesial marginal ridge (/), bordering the mesial face of the crown ; 
the distal marginal ridge on the distal side (m), the buccal marginal 
ridges (n) descending from the point of the buccal cusp to meet the buc- 
cal terminations of the distal and mesial marginal ridges at the angle 
formed by the junction with the buccal lateral lobes (o), and the lingual 
marginal ridges (_p), descending from the lingual tubercle to meet the 
lingual termination of the mesial and distal marginal ridges. 

The triangular ridges descend from the cusps toward the centre of 
the tooth and unite at the central groove. In defective teeth they do 
not fuse, leaving a fault or fissure which becomes the seat of caries. 
This groove or sulcus extends from one lateral marginal ridge to the 
other mesio-distally (>■) and widens into the mesial and distal sulci at 
each end. The triangular grooves (s) run from the mesial and distal 
sulci toward the mesial and distal angles, dividing the marginal ridges 

3 



34 MACROSCOPIC ANATOMY OF THE HUMAN TEETH 

from the triangular. They also become the seat of caries in imperfectly 
formed teeth. 

The neck of the first bicuspid is compressed or spindle-shaped (t), 
the enamel line rising on the buccal and lingual sides and dipping 
down on the mesial and distal. The enamel margin tapers off gradually 
on to the root. A wide, deep depression usually occurs (u) on the mesial 
side of the neck, leading to the groove on the root. On the distal face 
this is not so well marked. 

The root is much flattened mesio-distally, with a decided groove ex- 
tending up both sides. This grooving tends to cause bifurcation of the 
root, which actually occurs in one-third of the cases, especially in persons 
of strong build. This bifurcation is a persistent relic of lower forms 
of the premolars, as in the apes. 

The root canal is flat at the neck, and nearly always bifurcated, even 
when the root is not separated. This is readily seen by holding a bicus- 
pid having one root, up to the light, when the central portion will be ob- 
served to be translucent. The usual bifurcation necessitates the search 
for both canals in every case in treating this tooth. 

The upper second bicuspid (w) approximates the first on the distal 
side, and is similar to it in every way, except that it is usually smaller and 
more rounded in all directions. The sharp features, conspicuous ridges, 
etc. are not so strongly marked. The cusps are reduced, the ridges more 
rounded, and the morsal face more flattened, and it is often wrinkled. 
The triangular ridges are more likely to be united, thus making the crown 
stronger. The crown is thinner mesio-distally. The neck is more 
rounded or oval. 

A most conspicuous difference is in the root, which is narrower labio- 
lingually, is more rounded, and is rarely bifurcated. It is sometimes 
cylindrical or cubical in form. It is disposed to be turned, and is often 
crooked. The pulp canal is single and readily entered. 

13. The Lower Bicuspids. — These are placed next after the lower 
canines on the distal side. In form they are not truly bicuspid, for the 
first is unicuspid and the second is tricuspid in the pure typal forms ; 
but they are arbitrarily termed bicuspids on account of their position as 
compared with the upper bicuspids, which are typically bicuspid. 

The architectural form of these teeth is that of the single cone, the 
crown being augmented in various directions by the addition of cin- 
gules to the primitive cusp. 

The lower first bicuspid is a well-formed transitional tooth, for it- 
grades from canine to bicuspid and is typically composite. It more 
closely resembles a canine than a bicuspid in its usual form, because 
the inner cusp is almost suppressed and is rarely as large as the outer 
one (Fig. 19, a). In fact, it looks like a canine with a cingule raised 



THE BICUSPIDS. 



35 



upon its inner face. This cusp is really a cingule, for it is rarely raised 
to the full height of a cusp. 

It varies much in size from a mere point on the basal ridge (b) on 
through various degrees of development, up to a full cusp as large as 
the buccal cusp, when the tooth becomes a true bicuspid. The tooth is 
therefore essentially a primitive unicuspid premolar, of the form of this 
tooth in some of the lower primates. 

The buccal face (c) is caniniform, or a long oval in outline with 
the cusp rising as an abrupt point above it. The angle of the junc- 
tion of the marginal ridges may stand out prominently. The face 




The lower first bicuspid. 

curves markedly toward the lingual side, so that the buccal cusp becomes 
central to the long axis of the tooth (a). The cervical border is rounded 
at its margin and convex from side to side. The lobes are not marked. 

The lingual face (d) is convex from side to side and straight vertically, 
but is not perpendicular, as it is directed toward the lingual side. Its 
height depends upon the height of the lingual cingule, which varies from 
a mere buccal ridge through various degrees up to the full-sized cusp. 

The mesial and distal surfaces are of similar form, convex from side 
to side (a, b) slightly flattened at the cervical border and flaring out to 
meet the full marginal ridges, which are round and prominent. The 
prominence of these ridges and the inward inclination of the lingual 
face gives the crown a decided bell shape, tapering to the neck (d). 

The morsal surface (e) is peculiar and differs from every other tooth 
in its great variability and the extremes which it may present, from 
being a full bicuspid to a mere canine. This face is nearly circular in 
outline, the widening of the lateral surfaces by the spreading of the 
marginal ridges (/,/) adding to the width. The buccal cusp (g) is large 
and prominent, and is also drawn toward the centre of the tooth to 
accommodate the occlusion. Sometimes it is high and sharp when the 
lingual cusp is reduced, and is low and blunt when the latter is en- 
larged, — appearing to have an inverse ratio in size to the inner cusp. 
The lingual tubercle or cingule varies much in size, from a mere point 
on the basal ridge, above the cervical border, to a pronounced cingule, 
a larger cingule, a small cusp, then a full cusp, the basal ridge (h) 



36 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

being raised with it. The ridges are the mesial and distal marginal 
ridges (i, i), which are bowed out round and full and are always pro- 
nounced ; the buccal marginal ridges (/,/), leading down from the buc- 
cal cusp to form an angle with the mesial and distal marginal ridges ; 
the basal ridge, when the lingual cingule is lowered (6) ; and the tri- 
angular ridge of the buccal cusp, which is always large and when the 
inner tubercle is reduced leads down as a high central eminence. The 
lingual cingule, as a rule, possesses no triangular ridge. 

The central groove usually crosses the central ridge (k), but not 
always, being often bowed around its lower termination. Sometimes the 
ridge is crossed by a sulcus. The groove terminates in a sulcus at each 
end, with slight triangular grooves branching up on the buccal cusp. 
The neck is usually oval on section, being much constricted, the crown 
flaring upward from the cervical portion, giving the crown the well- 
known bell shape. The enamel line dips but slightly, being usually 
level on all four sides. The buccal border sometimes presents a prom- 
inent ridge. 

The root is single, long, tapering and may be nearly round, but is 
usually flattened mesio-distally. It is sometimes thick the greater part 
of its length, and terminates in an abrupt, round, blunt apex (c, <i). It 
is very liable to be crooked. It is rarely bifurcated and does not pre- 
sent grooves on its lateral faces. 

The pulp canal is constricted and flattened at the neck, and the back- 
ward inclination of the teeth makes it difficult to enter. The possibility 
of the root being crooked and the peculiarity of its anatomical rela- 
tionships l also increase the uncertainty of treatment, which makes the 
pulp canals of the lower bicuspids difficult to deal with. 

The lower second bicuspid approximates the first on its distal side. 
It resembles the first as regards the general form of 
FlG - 20 - the crown, its tapering bell shape, the constriction of 

the neck, and the shape of the root. In all these 
features there is little difference between these teeth, 
and the description of the first will apply also to the 
second bicuspid. 

The morsal surface, (Fig. 20), however, differs very 
materially from that of the first. This is circular in 
The morsai surface of outline like the first, and the buccal cusp is full and 

the lower second bi- , , , s , , , , • t • n i i 

cuspid rounded (a), but the inner cusp is divided by a groove 

(b) running over it, into two parts, so that it is really 

divided into two tubercles. This makes the lower second bicuspid in its 

typal form a tricuspid tooth ; so that it differs from the lower first, which 

has but one cusp, and from the others, which have but two cusps. The 

1 See page G06, Chapter XXI., on Extraction of Teeth. 




THE MOLARS. 37 

lingual tubercles vary much in size, so that one may be suppressed and 
the tooth seem bicuspid. The mesial lingual tubercle (c) may be of 
large size and be developed at the expense of the distal id) ; this may 
be a mere cingule on the distal marginal ridge and appear on the distal 
side, but it is always present. 

The morsal groove (e) is triangular in design, passing between each 
of the three tubercles. A well-marked triangular ridge descends from 
each of the cusps. 

The tricuspid form of the morsal surface of this tooth is, of course, 
a reproduction of the trituberculate premolars of the lower primates, 
and of still lower mammals, although the triangular form of the crown 
is lost in man. 

The Molars. 

14. The Tuberculate Teeth. — Molar teeth appear early in the scale 
of vertebrate life ; mere crushing teeth are found in fishes and slightly 
tuberculate teeth in the reptiles. The grinders are of simple form in the 
lowest vertebrates. The Bruta have simple, flat-crowned molars, which 
are undifferentiated and used merely for crushing. Tuberculate molars 
appeared early in the placental mammalia, the trituberculate molars being 
found in numerous fossil species, which are the typal form and forerunners 
of the tuberculate molars in the higher mammalia. The simple-crowned 
tooth with a single tubercle (haplodont, Cope), becomes duplicated and 
doubled, with a crown supporting several tubercles (bunodont). The 
transition from simple to complex teeth is accomplished by the repeti- 
tion of the type in different directions and the addition of cusps and 
roots both laterally and longitudinally of the jaw. The upper molar is 
formed by the addition of the third cusp to the bicuspid type and has 
three roots, Avhich support three or four tubercles. Lower molars con- 
sist of four cones which support four or five tubercles. The lower mo- 
lar is therefore the more complex tooth. The bicuspid is more complex 
than the canine, the upper molar than the bicuspid, the lower than the 
upper molar. 

The molar teeth of man are bunodont in form, i. e. they have simple 
rounded tubercles on the grinding face. They are of simple and primi- 
tive type, and indeed are most like the molars of the bears and other 
omnivorous animals. They are not highly specialized like those of the 
carnivora on the one hand with high sharp blades for cutting flesh, nor 
like those of the herbivora on the other, which are extended laterally for 
grinding tough vegetable fibre. They are of low organization as regards 
their functional development. 

The molars in man are twelve in number, three on each side of each 
jaw, and are placed at the rear of the arch, opposite the strong triturat- 



38 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

ing muscles, for the purpose of crushing and masticating food. They 
are important factors in alimentation and contribute to the function of 
digestion by preparing food for the stomach. Their loss impairs this 
function seriously and leads to derangement of the stomach by over-tax- 
ing it with imperfectly masticated food-substances. 

15. The Upper Molar. — The typical upper molar is formed by the 
fusion of three cones, as is plainly observed in the three roots and the 
three tubercles (Fig. 21, A). The tricuspid molar, therefore, is a primi- 
tive form, and is rarely seen in man, the normal form being quadritu- 
berculate. The fourth additional cusp, the disto-lingual (b), is merely 
a supplemental cusp added to the crown. An upper molar is, there- 
fore, composed of three tubercles, and a cingule which has not yet 
developed a root to support it. The trituberculate molar is the primitive 
form of this tooth, the quadrituberculate appearing later, and is found in 
only a few living forms, as some of the lemurs and the insectivorous 
and carnivorous mammalia. In man there is sometimes a reversion of 
the upper molar to the trituberculate form, which is a marked degeneracy 
in the form of this tooth. In an analysis of this tooth, therefore, the 
mesio-buccal tubercle (c) is the canine cusp ; the mesio-lingual, the bicus- 
pid cusp (d) ; the disto-buccal, the molar cusp (e), and the disto-lingual 
is but a supplemental cusp, — it is not a true cusp, as it has no root to 
support it. 

The architecture of the upper molar presents some interesting features. 
We observe that the crown is in a general way a geometrical form, a 
cube (/), when perfect and symmetrical. It is suggestive of symmetry, 
but when taken with the root form is not quite perfect, for it is sup- 
ported on three roots instead of four to correspond with the four tuber- 
cles at the four corners. So it lacks the " harmony of adequate sup- 
port," which is a cardinal principle in . architecture. But the crown 
separately is a symmetrical form, a cube, although the angles are rounded 
off and the corners and points are toned down and not acute. We no- 
tice that there are four strong columns, one at each of the four corners 
(g). They are connected on the four sides by the marginal ridges acting 
as strong connecting arches (h). These arches are related to the col- 
umns of the crown, and both are impressively proportioned. The cusps 
may be likened to the capitals of the columns, and the descending mar- 
ginal and triangular ridges to the cornice, gathered together to form the 
capitals. The triangular ridges may be considered girders (i), bind- 
ing the four together and also bracing the square obliquely. Or, the 
four triangular ridges running to the centre may be regarded as half- 
arches or buttresses, supporting the roof vault, — the grinding face. 
Other elements could be marked out in an architectural study of the 
crown of this tooth, showing its beautiful design and symmetry. 



THE MOLARS. 



39 



The upper first molar approximates the second bicuspid on its distal 
side. There is a marked and abrupt change in form, as the molar has 
double the number of cusps of the bicuspid,— being formed like two 
bicuspids fused together. The four tubercles mean an extension of sur- 
face and a further adaptation to functional requirements. The crown 
is large and cubical in form, and more or less rounded. 

Fig. 21. 





g h i 



Architectural diagram. 






The upper molar. 



The buccal face (K) is wide and rounded. It is twice the width of 
the bicuspids. It is broadest at the morsal margin, narrowing upward to 
the cervix, where it is widely rounded or arched. A vertical depression, 
the buccal groove (7), extends from the cervical border to the morsal 
margin, dividing the face into two oblong rounded eminences, the mesial 
and distal buccal lobes (m m). 

The lingual face (iV) is more rounded than the buccal, the cervical por- 
tion being the most convex (o), the mesial and distal sides being depressed 
toward the single lingual root. The morsal half is divided by the 
lingual groove (q), which descends over the lingual marginal ridge be- 
tween two lobes, the mesial (V) and distal (p), which are usually much 
rounded. The morsal half of the face curves toward the grinding sur- 
face. The mesial lobe sometimes presents the lingual cingule (s), a 
sort of fifth tubercle of greater or less size. A groove branches from 
the lingual groove and extends over, between the cingule and crown. 

The mesial face (r) is flat longitudinally, descending from the marginal 
ridge to the cervix in a nearly straight line. Bucco-lingually it is 



40 



MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 



convex, nearly flat at the marginal ridge, and rounded at the cervix, 
being depressed toward the lingual root. Sometimes a depression from 
the bifurcation of the mesio-buccal and lingual roots extends part way 
up on the face (u). 

The distal face is similar to the mesial except that it dips more 
toward the cervix, and is, perhaps, more rounded toward the lingual 
root. 

The morsal surface (Fig. 22) is the most important part of this tooth, 
and shows features that make it interesting and unique. The abrupt 



Fig. 22. 






d h j c 

The morsal surface of the upper first molar. 

change from the bicuspid form is notable, for there are presented four 
cusps, a doubling of the number ; the outline of this face presents a 
square form with tubercles at each corner, the mesio-buccal (a), the 
disto-buccal (6), the mesio-lingual (c), and the disto-lingual (d) ; the lat- 
ter is erratic and may be either pronounced or quite reduced in size. 

There are four marginal ridges — the mesial (e), buccal (/), distal (g) 
lingual (h), the oblique (£), and the four triangular ridges (j). The oblique 
ridge connects the mesio-lingual with the disto-buccal tubercle and is 
really the remnant of the marginal ridge of the tricuspid molar ; the 
fourth cusp, the disto-lingual, being raised up on the disto-lingual side. 
The four triangular ridges descend from the four tubercles toward the 
centre of the tooth, the oblique ridge being formed by the fusion of the 
triangular ridges of the mesio-lingual and disto-buccal cusps. 

There are two fossse (k), one mesial and the other distal to the oblique 
ridge. Sometimes the latter is cut by a groove or sulcus (I) which 
extends from the mesial to the distal fossa. Sometimes by the reduction 
of the disto-lingual lobe and cusp, the mesial fossa is extended and 
becomes central to the crown. A groove extends from the mesial fossa 
over the buccal marginal ridge (m) quite on to the buccal face, dividing 
the mesial from the distal buccal lobes. A groove also extends over 
the lingual marginal ridge (n) down upon the lingual face, dividing the 
lingual lobes. When this groove becomes a fissure, caries ensues and 
the disto-lingual cingule readily breaks away, this cingule being a weak 
feature in the mechanical design of this tooth ; cutting the distal mar- 
ginal ridge also weakens this cusp. The triangular grooves branch from 



THE MOLARS. 41 

the two fossae on to the cusps, dividing the triangular from the marginal 
ridges. 

The neck of this tooth is of rounded rhomboid form on section (o), 
widest at the buccal side. The enamel is almost level on all four sides, 
dipping downward slightly on the mesial and distal. A depression 
occurs at the bifurcation of the buccal roots, and an inward inclination 
on the mesial and distal sides. 

The roots are three in number (Fig. 21), two on the buccal side, 
which are small and flat or round, and one on the lingual side, which is 
large and rounded. The roots are usually separated, but may be found 
united, by a septum of cementum, in various directions. The mesio- 
buccal root is the larger of the two buccal roots, and forms a second 
turning-point or spring of the arch. All the roots are slightly bent 
and may be very crooked. 

The pulp chamber branches into three canals, one in each root. The 
lingual canal is large and open and is readily entered. The canals of the 
two buccal roots are small and fine, and, with the possibility of crooked- 
ness in the roots, present the most difficult problems as to treating and 
filling found in the whole denture. 

The upper second molar is similar to the first in some respects but 
very different in others. It is rather smaller, is not usually full and 
square, but disposed to become rhomboid in form (Fig. 23, o, 6), by 
disto-mesial compression. 

The buccal face is similar to that of 
the first molar, and the same description 
will apply to it. If any difference is 
found it is that the face is strongly com- 
pressed from front to back, and the disto- 
lingual cusp is more reduced as a con- 
stant feature. 

The lingual face (c) is different from 6 mi _ / . 

a J x ; The upper second molar. 

that of the first molar in that by the sup- 
pression of the disto-lingual tubercle (d) and the distal lobe, the mesio- 
lingual lobe is enlarged so that it occupies the entire face, which is full, 
rounded, and convex (e). It is rarely divided into two lobes as in the 
first molar, owing to the enlargement of the mesial lobe and the pushing 
backward of the oblique ridge, which throws the lingual groove on to 
the disto-lingual angle (d) ; or the groove may be absent altogether. 

The mesial and distal faces are similar in form to those of the first 
molar, being perhaps more flattened. 

The morsal face is similar to that of the first molar, except that the 
tubercles are less pronounced and the distal ones are reduced in height 
to accommodate the upward curve of the line of occlusion at this 




42 



MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 



point. The disto-lingual cingule is smaller than that upon the first 
molar, and is often barely marked. This throws the oblique riclge more 
to the distal side and enlarges the mesial fossa. The various grooves are 
the same as on the first molar, except that one, the lingual, may be lost. 

The neck is less regular in outline than that of the first molar, as the 
crown varies so much in shape. It is more flattened mesio-distally and 
depressed toward the roots. 

The roots are the same in number and general form as in the first 
molar, but spread less and are more irregular in form. They may con- 
verge or be crooked, or may be fused together. This makes the pulp 
canals more difficult to treat. Sometimes the three roots are completely 
fused, as in the third molar, and the canals may coalesce ; or the canals 
of the two buccal roots may run into one. The irregularity and uncer- 
tainty of the form of the roots make this tooth difficult to deal with in 
treating its pulp canals. 

16. The Lower Molars. — The lower first molar approximates the 
lower second bicuspid on its distal side. It is the first of the true grind- 
ers of the lower jaw and the largest tooth in the dental series. Unlike 
the upper molars the transverse diameter is less than the mesio-distal. 
The greater width is found across the base of the disto-buccal tubercle. 
The crown is square or trapezoidal in form, depending on the size of the 
fifth tubercle. Being quinquituberculate, the crown is broadened by the 
multicuspid grinding face. The buccal face is inclined toward the centre 
of the tooth, for its morsal half, to accommodate the occluding teeth. 

Architecturally, the tooth is formed of four cones (Fig. 24, A), and 




Architectural' diagram. 

a f 





The lower first molar. 



may be roughly divided into four quarters. There are four primitive 
cones with their tubercles and one cingule in the structure. 



THE MOLARS. 43 

The morsal surface (B) is trapezoidal in outline, the buccal line 
being the longest. The buccal angles are acute, while the lingual 
are rounded and obtuse. 

There are five tubercles, two on the lingual margin and three on the 
buccal. They are named the mesio-buccal (c), median buccal (d), disto- 
buccal (e), disto-lingual (/), and mesio-lingual (g). These tubercles are 
less obtuse and more rounded than those of the other grinding teeth, the 
mesio-buccal usually being the largest, the others are not so prominent, 
rarely raised and sharp. 

The ridges are : the marginal ridges — buccal, distal, lingual, and 
mesial — anc ] the five triangular ridges descending from the five tuber- 
cles toward the centre of the tooth. 

The grooves and sulci upon the morsal surface are very irregular. A 
deep sulcus traverses the face from the mesial to the distal marginal 
ridge. A groove runs off toward the lingual side, dividing the lingual 
cusps (i), sometimes cutting the lingual marginal ridge, but rarely 
reaching over on the lingual face. A groove runs toward the buccal 
side, dividing the mesio-buccal from the median tubercle (j), cutting 
the marginal ridge and extending over quite on to the buccal face. This 
groove often becomes the seat of caries owing to the enamel structure 
being faulty. Another groove extends toward the disto-buccal angle (&), 
dividing the median from the disto-buccal tubercle, and rarely extends 
over on to the buccal face. A groove may extend distally cutting the 
distal marginal ridge (/), and one mesially cutting the mesial marginal 
ridge (m), but these are not usually marked. The triangular groove run- 
ning up on each side of the triangular ridges (n) divides these from the 
marginal ridges. Supplemental grooves may divide the triangular ridges 
again. The pits at either end of the sulcus may become the seat of caries 
through faulty formation. 

The buccal face (c) is an irregular trapezoid in form, the morsal margin 
being longest ; the mesial and distal sides converge toward the cervical 
border, which is rounded. The morsal margin is broken by the three 
tubercles rising upon it. The buccal face is convex in all directions, 
that from the morsal to the cervical borders being the most marked 
owing to the morsal half converging toward the centre of the tooth. 
The buccal groove (o) leading over from the morsal face, divides the 
face into two lobes which are full and rounded. Sometimes the disto- 
buccal groove cuts off another lobe, thus making three lobes on the buccal 
face. These grooves sometimes lead .to the cervical border, but usually 
terminate in the middle of the face in a pit, which may become the seat 
of caries through faulty formation of the enamel. 

The Ungual face (D) is wide, rounded, smooth and convex, rather 
straight perpendicularly, leaning in the lingual direction. It forms a 



44 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

sharp angle with the morsal surface, which is surmounted with two 
tubercles. Sometimes, but rarely, the lingual groove passes over on to 
this face. 

The mesial and distal faces (s) are wide and flattened transversely, 
but convex vertically. They are trapezoidal in outline, the morsal 
border being longer. The cervical border is more convex, and dips 
toward the neck of the tooth. 

The neck (t) is very regular in outline and contour. It is approxi- 
mately square with all four sides depressed in the centres. The mesial 
and distal are depressed at the origins of the grooves leading down 
upon the roots ; the lingual and buccal are depressed at the bifurca- 
tion of the roots, the depression, which is wide and deep, extending up 
on to the neck, especially upon the buccal side. The enamel line is 
quite irregular, dipping down on the lingual and buccal, and leading 
well up on the mesial and distal sides. 

The roots are two in number, placed with their longer diameter trans- 
versely to the jaw. They are wide bucco-lingually, and flat and narrow 
disto-mesially, being situated distally and mesially to the crown. The 
posterior is formed of the two posterior cones, and the anterior of the 
two anterior cones (A). This is plainly shown in the formation of the 
roots, which are grooved both distally and mesially, and in the tendency 
to bifurcation, which sometimes actually occurs. They divide close to 
the crown, so that the grooves of bifurcation extend well up on the 
neck. The distal root is thicker and more rounded than the mesial, 
the latter being more flattened, with the grooves deeper, and it is more 
often bifurcated. Both are deflected from the median line. 

The pulp canal is shaped like the roots, with two main branches. 
The distal branch is the larger, being round and open, as the root is more 
rounded. The mesial branch is flat and spindle-shaped, being difficult 
to enter, and usually having two sub-branches following the buccal and 
lingual divisions of the root. These sub-branches are small and hair- 
like and troublesome to enter. 

The lower second molar (Fig. 25) differs from the first in many 
respects. It is of the same general form, but is more quadrangular, as 
it has but four tubercles. It is more rounded and symmetrical than the 
first, the four cones and four primitive tubercles being well marked. 
The absence of the fifth tubercle leads to most of the differences between 
the second and the first molar. 

The morsal face (c) has but four tubercles, one at each corner of the 
face, differing from that of the first molar, which has five. The fifth 
tubercle rarely appears in the higher races of mankind, but is some- 
times found in the low and savage races, and occurs regularly in the 
apes. It is not uncommon in the negro, but is absent as a rule in 



THE MOLARS. 



45 



the European races. The tubercles are symmetrical, rounded and 
obtuse, the lingual being, however, sharper than the buccal. 

The sulci describe a cruciform shape, separating the four tubercles 
symmetrically from each other. The buccal groove sometimes continues 
on to the buccal face, rarely to the lingual. The triangular grooves 
run up on the morsal triangular ridges. The marginal ridges are well 
marked, the mesial and distal being often divided by grooves. The 
triangular ridges are usually well marked, leading to the centre of the 
tooth. They are full and strong. 

The buccal face (d) is convex and of more regular form than that 
of the first molar. It is divided into two lobes (e, e) by the buccal 



Fig. 25. 




Ti h 

The lower second molar. 



groove (c/), which is rarely deep. A pit is often found in the centre 
of the face, which may become the seat of caries. The face is curved 
toward the centre of the tooth, as in the first molar. 

The lingual face is similar to that of the first molar, but may be more 
rounded toward the morsal border. It is symmetrically convex in both 
directions. 

The mesial and distal faces (f) are similar to those of the first molar 
except that, the crown being smaller, they may be more perpendicular, 
but are well rounded. 

The neck (g) is more regularly formed than that of the first molar, 
the margin of the enamel line being quite as irregular. It may be more 
constricted. 

The roots (h, h) are similar to those of the first molar, but are more 
rounded in shape, are usually crooked, and on that account difficult to 
treat. 

The pulp canals are similar to those of the first molar, but the tend- 
ency to crookedness renders treatment quite difficult. The direction 
of irregularity of form is so uncertain that no rule can be applied to it. 

17. The Third Molars. — The upper and lower third molars can best 
be described together, on account of their similar eccentricities. They 
are very irregular as to the time and to the frequency of their appearance 
in civilized man. About one-half of the individuals of European races 




46 MACROSCOPIC ANATOMY OF THE HUMAN TEETH 

erupt them at the normal period, i. e. seventeen to twenty-one years of 
age. In one-fourth they erupt at irregular intervals to the thirtieth 
year, and in the remainder they may appear later, or the first, second, 
third, or all of them, may be absent altogether. In one series of forty 
adult skulls observed, twelve had one or more absent. The absence and 
other erratic peculiarities of these teeth sometimes seem to be hereditary 
and can be traced in families through several generations. 

This tooth is often reduced in size and may be a mere peg (Fig. 26, a). 
It is of very irregular form in civilized races, but is as large and as well 

formed as the other molars in most 
races low in the ethnological scale. 
The contraction of the jaws through 
disuse has much to do with the mal- 
development of this tooth, and it is 
often so cramped for room as to pro- 
duce distressing irritation which ne- 

The upper third molar. . . 

cessitates its removal. Impaction 
and malposition of the third molars render them difficult of extraction 
and are the fruitful source of many serious lesions. (See the chapter 
on Extraction of Teeth.) 

The upper third molar is more or less similar to the other upper 
molars when perfect and well developed, but it is very erratic as to form 
and structure. 

This tooth, when well formed, is of trituberculate form (6), the 
disto-lingual cingule being suppressed. This cingule diminishes grad- 
ually from the first molar, in which it is well formed, to the second, 
where it is reduced, then to the third, where it is almost or entirely 
absent. The oblique ridge thus becomes the posterior marginal ridge 
(c), as in the typical trituberculate molar. The three tubercles are 
reduced and rounded. The sulci usually degenerate into fissures, as 
the formation of this tooth is notoriously faulty. The enlarged mesial 
fissures thus become the seat of extensive caries. 

The buccal face resembles that of the first and second molars, but is 
more rounded. 

The lingual face (d) is full and rounded, with but a single lobe, owing 
to the reduction or absence of the disto-lingual tubercle. 

The mesial face (e) is similar to that of the second molar, but reduced, 
and the distal face is round and short, as no tooth succeeds it in the rear. 

The neck is constricted and tapers toward the conate roots. It is of 
a rather rounded triangular shape. 

The three roots of the upper molars are, in the third, usually more 
blunt, conate, short in form, and may curve backward. In lower races 
and sometimes in individuals having strong osseous organizations, the 



THE MOLARS. 



47 



Sometimes there are multiple 
various directions and may 




The lower third molar. 



typical three molar roots are found, 
roots, which are likely to be curved in 
have decided hooks. 

In the large conate root, the pulp canals usually coalesce, but in 
cases in which the root is divided there will also be division of the 
pulp chamber. 

The lower third molar is similar to the other lower molars in 
general form (Fig. 27, a), but is probably not so erratic and not subject 
to such extreme variations. The crown is 
quadrangular in section, the angles rounded. 

On the morsal face (6), there are four 
principal tubercles as in the second molar, 
but this may be supplemented by the ex- 
tension of the disto-marginal ridge into a 
cingule or heel (e). This heel is rather 
erratic ; it may be large or small, thus 
modifying the size of the morsal sur- 
face. Sometimes the face is wrinkled and, like this tooth in the 
orang utan, the sulci exhibit the cruciform shape similar to that of the 
second molar. The many grooves leading away from the main sulcus may 
be imperfect and become the seat of caries. The buccal groove running 
from the morsal on to the buccal face (a) is very subject to imperfection. 

The four lateral faces are similar to those of the second molar, except 
that the distal is more convex and full, and often very prominent if the 
fifth cingule is well developed. 

The neck is of similar shape to that of the second molar. 

The roots are similar to those of the other lower molars, but generally 
smaller as compared with the crown (d). They are usually divided like 
the others, but the two may be fused together, or be closely opposed. 
In either case they are usually projected distally more or less, leading 
backward into and under the ramus, thereby rendering extraction of 
this tooth difficult and dangerous, especially where the maxilla is of 

Fig. 28. 



-^ 



39 



5 
ft. 




The fourth molar. 

dense structure or where there is impaction. The roots are usually 

more rounded, especially the distal one, than those of the other molars. 

The pulp canals are generally divided, whether the root is or not. 



48 MACROSCOPIC ANATOMY OF THE HUMAN TEETH 

As the roots are usually crooked, the difficulty of entering them is 
increased, as the canals follow the form of the roots. 

Fourth molars sometimes appear as supernumerary teeth, and are 
either fused to the upper third molar in a variety of uncouth forms 
(Fig. 28, a) or erupt separately as mere peg-shaped teeth between the 
buccal faces of the second and third molars (6) or at the distal aspect 
of the latter tooth. The fourth molar rarely appears as a full molar, 
except in some of the large-toothed races, as negroes, Australians, etc., 
and then usually in the lower jaw. Among the negroes in Africa the 
fourth molar is sometimes found in full form as a typical molar. 



Fig. 29. 






a • 

Negro jaw with fourth molar 



T" ." 



The Deciduous Teeth. 

18. The deciduous teeth are those which appear in infancy and 
serve the purpose of dental organs during the first years of the develop- 
ment of the individual, until the jaws and their environment are ready 
for the larger, permanent teeth to come into place. They bear a direct 
relationship to the conditions of the digestive apparatus and the food 
required at that early stage. The food of infancy being simple and 
requiring little mastication, the deciduous set are small and insufficient 
for the reduction of more resisting substances. As these foods come to 
form part of the dietary, the larger teeth of the permanent set appear, 
and perform the duties of higher functional activity. 

The crowns of the deciduous teeth resemble, in a general way, those 
of the permanent teeth which succeed them, except the deciduous 
molars (Fig. 30, a, d), which are very different from the bicuspids 
of the permanent set which displace them. 

The incisors of both jaws precede the analogous teeth of the same 
series of the permanent set. They are similar in form, but reduced (6), 
and do not have the main features so characteristically marked. They 
are infantile in form and function. The roots of these teeth are 



THE DECIDUOUS TEETH 



49 



resorbed at from the fifth to the ninth year, when the permanent incisors 
come into place, beginning with the lower centrals. 

The canines (c) of both jaws are still more reduced from the strong, 



Fig. 30. 




c d 

The deciduous teeth. 



full form of their permanent successors, and are but little more 
specialized than the incisors. They are of the same general form as 
the permanent canines, but much less developed. 

But in the deciduous molars are found some important features 
which mark distinctive differences. They are of true molar form as 
compared with the permanent molars, but they occupy the place of the 
bicuspids. There are no bicuspids in the deciduous set, the molars being 
of full molar pattern («, d). 

The deciduous molars of both jaws are of irregular, quadrangular 
form on the morsal surface, diverging rapidly outward to the neck, 
which presents a large buccal ridge standing out at the margin of the 
enamel, and is rounded off suddenly to the neck, which is much con- 
tracted. This thick ridge is characteristic of the deciduous molars and 
is absent in those of the permanent denture. It is somewhat more 
prominent and bulging on the buccal than on the other faces. In 
adjusting ferrule crowns to these teeth, the gold need not be carried 
beyond this ridge but burnished over it slightly. 

The morsal surface (e) of the upper deciduous grinders presents the 
characteristic pattern of the upper molars, four tubercles, oblique ridges, 
etc., but reduced and contracted. A distinctive feature is that the 
marginal ridges and angles are more acute and sharp than in the per- 
manent molars. Sometimes the two lingual cusps are reduced to one 
and the lingual border is rounded and crescentic. 

The second molar is larger than the first and the morsal surface is 
wider. 



50 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

The transverse diameter of the crowns of the upper molars is the 
longest. 

The lower molars (d) are similar to the permanent molars in pat- 
tern, but are more irregular as to the contour of the morsal surface (/). 
The tubercles may be higher than in the upper molars, and the tri- 
angular ridges more marked. The central fossa may be large and wide, 
or divided by the triangular ridges. The second molar is five-lobed, 
unlike the second permanent molar, which has but four cusps. The 
morsal face is decidedly trapezoidal in outline, the mesio-distal diameter 
being greater than the transverse. 

The roots of the deciduous molars are similar to those of the other 
molars, except that they are very divergent to accommodate the crown 
of the advancing bicuspids. They are thin and long, and difficult to 
enter and fill. The pulp chamber is large and open in the crown ; as 
a consequence of this caries soon reaches the pulp. Treatment and 
filling of the canals is difficult and uncertain. 

The Variations of Tooth Forms. 

19. The teeth may vary quite extensively from the typal forms which 
have been described, and these variations may be due to a number of 
causes. Through all degrees of variation, however, the type is still pre- 
served, unless the tooth form is quite destroyed by pathological causes. 

The general causes of variation may be enumerated as follows : 

(1) Incompleteness of development. 

(2) Reversion to primitive types. 

(3) Temperamental impress. 

(4) Pathological lesions. 

(1) Under incompleteness of development may be grouped all 
those varieties of stunted growth which are the effect of disuse and 
the consequent effort of Nature to reduce and suppress the teeth as 
useless parts. The third molar teeth suffer most from these suppressive 
attempts of Nature in the effort toward economy of growth ; next to 
these teeth, the upper lateral incisors are most frequently affected by 
reduction of size, stunted growth and suppression. Other teeth are 
rarely affected, or but very slightly, by this influence, except in rare 
cases. 

(2) Under the second head, reversion to primitive types, we have a 
variety of interesting phenomena in the form of parts of the human 
teeth which seem to be a zoological legacy. These consist of conspic- 
uous features which reappear aud seem to recall forms of the teeth 
observed in some of the lower animal orders, especially the quadrumana 
and insectivora. 

Among these features may be mentioned the curved upper central 



THE VARIATIONS OF TOOTH FORMS. 51 

incisor with the prominent cingule on the lingual -buccal ridge, making 
a notch which recalls the incisors of the moles ; the prominent cingule 
on the lingual face of the lateral incisor, which is not uncommon and 
recalls the form found in the insectivora and some of the quadrumana ; 
the extra-long, curved canine, with extra -large median ridges, which 
recalls the large forms of this tooth in the baboons and in the car- 
nivora ; the double root sometimes found in this tooth is also a re- 
version to the insectivorous type ; the three-rooted bicuspid is a quad- 
rumanous reversion ; the upper tricuspid molar is a primitive typal 
form, leading back to the lemurs and beyond them to the early typal 
mammals found in fossil formations ; the notched and grooved incisor 
recalls the divided incisor of the Galeopithecus ; the double-rooted lower 
incisors and canines recall insectivorous forms ; the unicuspid lower 
first bicuspid is an insectivorous type and is often quite marked in man ; 
the fifth cusp on the lower second molar is a quadrumanous rever- 
sion ; the wrinkled surface of the lower third molar is like that of the 
orang. 

There are other features that might be named illustrating the work- 
ings of the law of atavism, by which parts once lost in evolution may 
reappear and be reproduced. 

(3) Under the third head, temperamental impress, may be noticed 
those differences of form and structure which have relation to the domi- 
nant temperament in the constitution of the individual. Great differ- 
ences exist between the teeth of different persons, and these are mainly 
dictated by temperament. 

The teeth of the primary basal temperaments present the following 
physical peculiarities, which are characteristic of the particular tempera- 
ment : 

The bilious temperament presents teeth that are of a strong 
yellow ; large, long, and angular, often with transverse lines of forma- 
tion, without brilliancy, transparency, and of but slight translucency ; 
firm and close set and well locked in articulation. 

The sanguine temperament has teeth that are symmetrical and 
well proportioned, with curved or rounded outlines, and round cusps ; 
cream color, inclined to yellow, rather brilliant and translucent ; well 
set, and occlusion firm. 

The nervous temperament has teeth which are rather long, the 
cutting edges and cusps long and fine ; color pearl-blue or gray, very 
transparent at the apex ; the occlusion very penetrating. 

The lymphatic temperament presents teeth that are pallid or 
opaque, dull or muddy in coloring ; large, broad, ill-shaped, cusps low 
and rounded ; the occlusion lose and flat. 

Of the binary combinations ■• 



52 MACROSCOPIC ANATOMY OF THE HUMAN TEETH. 

The SANGUiNEO-BiLious has teeth which are large, with strong edges 
and large cusps ; color dark yellow, and quality good. 

The nervo-bilious has teeth that are long and narrow, with long 
cusps ; color yellowish or bluish or both combined ; the enamel strong. 
the dentin soft. 

The lympho-biliotts has teeth that are large, with thick edges and 
short thick cusps ; yellowish in color ; enamel of good structure and 
polish, and dentin fair. 

The bilio-sanguineous has teeth of average size, round arch, well- 
developed cusps and edges ; rich dark -cream color ; excellent in quality. 

The NERVO-SANGUINEOUS has teeth of average size, good shape, round 
arch, good edges and cusps ; rich cream color ; enamel and dentin of 
excellent structure. 

The lympho-sanguineous has teeth of more than average size, 
shapely edges and cusps, rounded arch ; color grayish cream ; enamel 
and dentin fairly good. 

The bilio-nervous has teeth variable in size and form, sometimes 
broad, again very long with more pointed and long cusps; the color 
generally bluish ; enamel fairly good, dentin soft and sensitive. 

The sanguineo-nervous has teeth of average size, good shape, 
round arch ; color grayish blue ; soft and frail. 

The bilio-lymphatic has teeth usually large, with thick edges, 
short thick cusps, and flat arch ; color yellowish ; quality good. 

The sanguineo-lymphatic has teeth of more than the average size, 
broad round arch ; color gray ; enamel and dentin poor. 

The nervo-lymphatic has teeth of average size, good shape, aver- 
age length, rather round arch ; color bluish gray ; soft and poor. 

Combinations of the binary temperaments are of the most common 
occurrence in individuals, but there is usually one basal temperament 
that preponderates over the others and gives its characteristic to the 
teeth as a predominating influence. 

(4) Under the fourth head, pathological lesions, are to be included 
all those disturbances of nutrition which eventuate in faulty formation 
of the teeth, whether due to specific hereditary diseases, mere malnutri- 
tion, idiosyncrasies, predispositions, defective functional life, etc. But 
this leads beyond the province of this chapter into the field of special 
pathology. 



CHAPTER II. 

THE EMBRYOLOGY OF THE DENTAL TISSUES. 

By R. R. Andrews, A. M., D. D. S. 



A clear understanding of the minute structure of the teeth can only 
be had through a study of the complex processes through which the 
tissue elements have had their origin or have derived their forms. 
The teeth do not belong to the bony skeleton of the body, but, like 
the hair, nails, etc., are parts of the dermal system. 

The origin of the tissues of the teeth is from two of the three 
germinal layers of the blastoderm, the epiblastic and mesoblastic layers. 
A transverse section through the blastoderm of a chick shows that the 
epiblast, or outer layer, is formed of cells like columnar epithelium ; 
their shape is probably due to lateral pressure of adjoining cells. It 
is from this layer that epithelium is formed, and epithelial tissue is the 
origin of the enamel. The mesoblast, or middle layer, is composed of 
cells said to be derived from both hypoblast and epiblast, but princi- 
pally from the latter. 1 They are merely nucleated structures, containing 
granules, the nuclei of the future cells of the connective tissues. In this 
state they have no cell-limit or wall ; as they grow older they accumu- 
late around themselves formed material. Only in maturer stages do 
these cells develop, on their surfaces, an optically distinct membrane 
or other structure. It is from the cells of the mesoblast that the em- 
bryonic connective tissue which forms the dentinal papilla originates. 

Development of the Jaws. 

As stated by Prof. Sudduth, 2 the first indication of the formation of 
the oral cavity is seen very early in the life history of the embryo. 
The superior maxilla arises from three separate points : on either side 
of the embryonic head a process springs from the first pharyngeal arch. 
The processes pass downward and forward, and unite with the sides of 
the nasal process. From the frontal prominence, the third process, the 
incisive, grows downward and fills in the space between the ends of the 
two preceding processes. By a union of these three processes the supe- 
rior maxillae are completed. The inferior maxilla is formed by buds 
growing from the first pharyngeal arch ; these buds grow rapidly until 

1 The three layers of the blastoderm are also designated as ectoderm, mesoderm, and 
entoderm respectively. 

2 American System of Dentistry, vol. i. p. 550. 

53 



54 EMBRYOLOGY OF THE DENTAL TISSUES. 

union occurs at the median line. The central portion of the arch thus 
formed, very soon after the union of the two lateral processes, becomes 
differentiated into a cartilaginous cord or band, which serves to strengthen 
the embryonic jaw. This is Meckel's cartilage. It is formed of two 
parts arising from the mallei of the ears and traversing both sides of the 
embyronic jaw to the point of union. While the jaw-bone is forming, 
Meckel's cartilage disappears by absorption ; some authorities believe it 
becomes ossified, forming part of the inferior maxilla. 

The Embryonic Mucous Membrane. 

If at a time just previous to tooth formation a section across the 
lower jaw is cut, it will be found to consist of a central mass of 

embryonic connective - tissue cells 
-, V edged on every surface by the in- 

nermost layer of the epithelium. 
; . - ? y-^'A-^ 1 This covering of epithelium is the 

Malpighian or mother layer, most 
j&fr.. o important to the dental histologist, 
.■.'""..'. '.A*<S8J?*825^^-' : because from it originate the en- 
^^l&^^JBE?: •< amel organs of the teeth, as well as 
^S EMy^'^" ' '" '' 3 the bulbs of the hair and the epi- 
ffl thelium of the glands. Thus early 
V- 1 ;;>' the Malpighian layer consists of 
cells somewhat like those of the 
connective tissue within, but thev 
Section of jaw, embryo of pig, showing the stain more deeply and are really 

appearance of mucous membrane before «,i -i- i -1-1 -i • ,-, . . . 

the formation of the enamel organ :l,epi- epithelial Cells, having their origin 

thelium ; 2, stratum Malpighii ■ 3, embry- f rom the Cells of the epiblast. This 

onic connective tissue. , T , . , . , 

Malpighian layer is, again, every- 
where covered by epithelial cells, which are continually formed by it. 

When the tissue is older, the cells of the stratum Malpighii become 
columnar or prismatic in shape, standing somewhat vertically over the 
embryonic tissue beneath. They have large round nuclei, and some 
authors have stated that they have no cell-wall. Just without these 
are larger cells, sometimes called youthful cells, and external to these 
the cells are larger and are more polygonal in form, representing 
the cells in their middle life, in which the cell-wall has increased in 
thickness, while the nucleus is found to be smaller. Those cells on 
the outer surface are the aged cells, consisting almost wholly of formed 
material. They in time lose their vitality, having undergone changes, 
until, from the fresh mass of protoplasm, they finally become thin, lifeless 
scales, which in adult tissue are constantly cast off during the life of the 
individual. They are reproduced from the cells of the stratum Malpighii. 



THE DENTAL RIDGE AND DENTAL GROOVE. 55 

Fig. 32. 




Section of jaw, embryo of pig, showing the epithelium highly magnified: 1, oldest epithelial 
cells ; 2, the younger cells ; 3, the infant layer, the stratum Malpighii ; 4, the embryonic connec- 
tive tissue. 

The epithelium, as has been stated, is derived from the epiblast, and 
is developed considerably earlier than is the embryonic connective tis- 
sue beneath. 



The Dental Ridge and Dental Groove. 
On that portion of the jaw which is to become the alveolar border, 



between the fortieth and forty-fifth days, 
there is seen a growth of cells, which looks 
as though it had been pushed up in the 
form of a smooth ridge. If a section is 
cut across the jaw at this time, and exam- 
ined, it will be found that this ridge con- 
sists of a mound of epithelial cells which 
some writers have called the maxillary 
rampart. This growth of cells is seen to 
have had a more energetic growth inward 
into the substance of the embryonic tissue 
than it has had outward, so that a groove 
containing epithelium is formed around the 
entire upper border of the jaw, and in this 
condition has been called the tooth band. 



Fig. 33. 




Section through the jaws of human 
embryo, showing developing en- 
amel organs. (Section by Dr. 
Sudduth.) 



56 



EMBRYOLOGY OF THE DENTAL TISSUES. 
Fig. 34. 




%*C 



X. /*"-*" •'• 





Section of lower jaw, embryo of pig, showing the first stage of growth in enamel organ : 1, epithe- 
lium ; 2, stratum Malpighii ; 3, dental groove ; 4, commencing growth of temporary enamel 
organ ; 5, Meckel's cartilage ; 6, forming bone of jaw. (Section by Dr. Sudduth.) 

The cells of the layer next the embryonic connective tissue are always 
more or less columnar. They are directly derived from, and are a part 
of, the stratum Malpighii. It was the loss of this epithelial tissue, per- 

Fig. 35. 




2, stratum 



Section of jaw, embryo of pig, showing growth of enamel organ : 1, epithelium : z, siraium 
Malpighii : 3, first stage in growth of enamel organ of temporary tooth ; 4, embryonic connec- 
tive tissue ; 5, developing bone of jaw. 



THE DENTAL RIDGE AND DENTAL GROOVE. 
Fig. 36. 



57 




\ 



*F 



9 

■HHwHi 

Section of jaw, embryo of pig, showing growth of enamel organ : 1, epithelium; 2, Malpighian 
layer : 3, second stage in growth of enamel organ ; 4, embryonic connective tissue. 

Fig. 37. 




Section of jaw, embryo of pig, showing growth of enamel organ: 1, epithelium; 2, second stage 
in growth of enamel organ ; '6, embryonic connective tissue. 



58 EMBRYOLOGY OF THE DENTAL TISSUES. 

Fig. 38. 



r 



*. 





Section of jaw, embryo of pig, showing growth of enamel organ and zone of dentin-forming 
tissue : 1, epithelium ; 2, enamel organ ; 3, zone of dentin-forming tissue. 

Fig. 39. 






Section of jaw, embryo of pig, showing growth of enamel organ and first stage in growth of dentin 
germ : 1, epitbelium ; 2, enamel organ ; 3, dentin germ. (The enamel organ has been pushed 
away from the dentin by the knife in cutting the section, leaving a space between the two.) 



THE DENTAL ETDGE AND DENTAL GROOVE. 



59 



haps by the action of too powerful reagents, which led Goodsir and his 
followers to describe the appearance of an open groove. The Goodsir 
theory had no foundation in fact, because no such open groove ever 
existed in that situation. 

The various foldings found in embryonic tissue no doubt are an ex- 
pression of an economic provision on the part of Nature in caring for 



Fig. 40. 




Section of jaw, embryo of sheep, showing growth of enamel organ and dentin germ: 1, 
mass of epithelium ; 2, enamel organ ; 3, dentin germ ; 4, growing jaw. 



large 



the tissue that is to be taken up by the expansion of the parts during 
its growth, as eventually they are all smoothed out. Rose's models 1 
show that the original inflection (stratum Malpighii) at an early stage 
divides into two portions, one of which, the outer, is nearly perpen- 
dicular and is intimately connected with the formation of the lip 
furrow, whilst that immediately under consideration passes almost 
horizontally backward into the tissue beneath. 

At about the forty-eighth day, from the lingual side of this groove, 
at a point where a tooth is to be formed, a portion of the stratum 
Malpighii is found growing into the embryonic connective tissue, in 

1 Models of Developing Teeth and Jaws. By Carl Rose, M. D. 



60 



EMBRYOLOGY OF THE DENTAL TISSUES. 



shape somewhat like a bud, and this is the first indication that a tooth 
is to be developed — the commencing growth of the enamel organ. 
This ingrowth increases, and assumes the shape of a tubular gland, 
pushing its way into the connective tissue. It may now be called an 
epithelial cord, and at the end farthest from the epithelium proper 
a growth of cells takes place, this part expanding from the multiplica- 
tion of cells within, which causes it to assume the form of a Florentine 
flask. 

Just at this time, at a point somewhere between this expanding part 
and the Malpighian layer above, a budding takes place from this cord, 
which is the commencing growth of the enamel organ of the permanent 
tooth. A change is taking place in the embryonic tissue just under the 
flask-shaped enamel organ ; a very active growth of cells is seen to be 

Fig. 41. 




Section of jaw, embryo of pig, showing growth of enamel organ and dentin germ: 1, enamel 
organ ; 2, dentin germ ; 3, growth of jaw ; 4, tongue. 



going on, and this activity results in the formation of a papilla, the first 
stage in the growth of the dentin germ. 

As the enamel organ enlarges by an increase of cells within it, the 
borders of its base grow inward, covering the dentinal papilla like a 
cap or hood, enclosing it at its base. The cells within the enamel 
organ are seen to have changed ; they are no longer like epithelial 



THE DENTAL RIDGE AND DENTAL GROOVE. 



61 



formations, but form a reticulum and have a stellate appearance 
when seen in section. 

While the change in form of the central cells of the enamel organ is 
taking place, the dentin germ is assuming the form of the future tooth- 
point. From the base of the dentin germ, connective tissue is being 

Fig. 42. 




Section of jaw, embryo of pig, showing development of temporary molar tooth : 1, enamel organ 

2, dentin germ. 



formed around the enamel organ, like the outer walls of a bag, this 
layer being the wall of the dental sacculus ; and when the enamel 
organ' is nearly enclosed, the epithelial cord that connects it with the 
Malpighian layer breaks up into epithelial clusters ; some of which 
wander toward the Malpighian layer, while others cluster to the wall 
of the sacculus, where it is supposed they become absorbed. In their 
origin the sacculus and dentin germ are identical, springing as they do 
from the embryonic connective tissue. 

At this time there is no evidence of a basement membrane, When 
the enamel organ and dentin germ become enclosed in the sacculus, it 
and its contents become the dental follicle, at which period calcifica- 
tion is about to commence. 



62 EMBRYOLOGY OF THE DENTAL TISSUES. 

Fig. 43. 







~ T~ 







Section of jaw, embryo of pig, showing development of temporary molar tooth : 1, enamel organ ; 

2, dentin germ. 

The Enamel Organ. 

The enamel organ is now in its perfected state. On examination 
it is found to be composed of three distinct cellular forms. The essen- 
tial layer is the ameloblastic layer of columnar cells which rests upon 
the dentin germ. These are the cells that are to become the enamel 
cells or ameloblasts. They have become changed by pressure into very 
symmetrical hexagons, four or five times as long as they are broad, with 
a distinctly marked nucleus in the part farthest away from the dentin 
germ. Only the sides of the cells are said to have membranes : they 
are without covering at either end. These cells are longer just over the 
point of the dentin germ and are shorter as they approach its base, being 
here very much like those of the outer layer, the external epithelium of 
the enamel organ. 

This outer layer is composed of cells which are roundish, a little 
longer than they are wide, and seem to be losing their columnar form. 
Indeed, soon after calcification has commenced these cells disappear. 1 

1 It is a question what becomes of them. Some authorities think that they are the 
origin of Nasmyth's membrane, but this is very doubtful, for investigation shows that 



THE ENAMEL ORGAN. 



63 



Just within these two epithelial layers there is found the second im- 
portant layer of cells, and this layer has been named the stratum inter- 
medium (see Fig. 55). The cells of this layer are intermediate in shape 



Fig. 44. 




Section of jaw, embryo of pig, showing development of dental follicle and first stage in the growth 
of the permanent enamel organ ; also the formation of walls of the sacculus : 1, epithelium ; 
2, Malpighian layer ; 3, enamel organ ; 4, dentin germ ; 5, outer wall of sacculus ; 6, inner wall 
of sacculus ; 7, bud of enamel organ of permanent tooth ; 8, growing jaw. 

between the ameloblasts and those of the stellate reticulum. The layer 
was first described by Hanover, and is thought to be a supplying and 
nourishing layer to the ameloblasts. Over these they remain, while 
everywhere else they disappear as calcification progresses. It is prob- 
able that they give birth to new enamel cells as the circumference of the 
enamel layer increases by growth. By careful examination it will be 
found that they are connected by minute processes with the enamel cells 
and also with the stellate cells of the central portion. Dr. Lionel Beale 
first made the statement that a vascular network lies within the stratum 
intermedium. This fact has recently been confirmed by other English 

they are completely lost some time before the completion of the calcification of the enamel. 
Just after a layer of dentin has been formed, everywhere upon its surface are seen the 
enamel cells, ready to form the enamel, and no trace of the outer epithelium can be seen. 
It has disappeared from that part in the perfected enamel organ. 



64 EMBRYOLOGY OF THE DENTAL TISSUES. 

workers, for Tomes mentions the fact that Prof. Howes and Mr. Poulton 
have demonstrated this vascular network in the stratum intermedium 
of the enamel organ of the rat. 

Dr. J. Leon Williams, in an article on " The Formation and Struc- 
ture of Dental Enamel," l demonstrates with his photo-micrographs the 
existence of this vascular network in the stratum intermedium of the 
rat which had been previously seen by these English observers, but it 
is to be remembered that this vascular network forms after the outer 

Fjg. 45. 





4 



W 

rZ-3 



V 



Section of jaw, embryo of pig, showing development of dentin germ and enamel organ of per- 
manent tooth : 1, epithelium ; 2, enamel organ ; 3, dentin germ ; 4, buuuing of enamel organ 
of permanent tooth ; 5, developing jaw. 

portions of the enamel organ have disappeared, and only when the con- 
nective tissue of the jaw is in contact with the cells of the stratum 
intermedium. 

The third form of cells fills up the central portion ; they appear 
star-shaped, and have been called the stellate reticulum of the enamel 
organ. Between the cells is to be found a fluid rich in albumin ; the 
consistence of this is somewhat like a jelly ; indeed, enamel organs 
have been called enamel jelly or enamel pulps. Tomes states that the 
function and destination of the stellate reticulum is not very clear. 
Enamel can be very well formed without it, as is seen among reptiles 

1 Dental Cosmos, February, 1896. 



THE ENAMEL ORGAN. 



65 



and fish, and even in mammalia it disappears prior to the completion of 
the enamel. It has been supposed to have no more important function 
than to fill up the space subsequently taken up by the growing tooth. 
Kolliker does not agree with this. He states that the stellate reticulum 
is certainly of great importance in the building up of enamel, and, 
owing to its richness in albumin and the gelatinous mass in its meshes, 
is, figuratively speaking, a pantry from which the enamel membrane (the 
ameloblasts) derives the material for its growth, — being some distance 
from blood-vessels. 

The cells of the stellate reticulum are characterized by the great 
length of their communicating processes. Dr. Sudduth thinks that 




Fig 


. 46. 






J' T > 














V 




|£^';-.' 






Section of jaw, embryo of sheep, showing development of dentin germ: 1, layer (portion of) of 
ameloblasts ; 2, external epithelium of enamel organ (most of the stellate reticulum has been 
washed out); 3, enamel organ of permanent tooth; 4, dentin germ; 5, whorls of epithelial 
cells caused by breaking up of neck or cord of enamel organ ; 6, part of stellate reticulum. 

this appearance is largely due to shrinkage. He says : " I fully believe 
that if we could examine these cells at once before any shrinkage occurs, 
we should be able to prove the fact that in life they are not stellate but 

5 



66 



EMBRYOLOGY OF THE DENTAL TISSUES. 



large polygonal cells." Dr. Williams has shown 1 that this supposi- 
tion of Dr. Sudduth is a fact. In his photo-micrographs he has 
clearly demonstrated the cell contents filling in the spaces between 
the stellate tissue. He shows them to be very perfect nucleated cells 
lying in the so-called stellate reticulum, which is really the slightly 
modified cell wall. 

The " stellate reticulum/' then, may be regarded as a storehouse of 

Fig. 47. 




Section of jaw, embryo of pig, showing developing tooth (section teased away from tooth to show 
the fold in the enamel substance) : 1, enamel organ ; 2, enamel substance not yet calcified ; 
3, layer of formed dentin ; 4, a fold in the enamel substance ; 5, dentin pulp ; 6, folds at base 
of dentin germ ; 7, developing bone. 

the calcium salts from which the first-formed layers of enamel are sup- 
plied. That calcium salts exist in the meshes of the stellate reticulum 
may be proven by placing a drop of dilute nitric acid on the slide when 
it passes under the cover-glass. The globules or granules which were 
noticed there disappear as the acid reaches them, and bubbles accumu- 
late and are forced out from under the glass cover. After the calcify- 
ing process commences and enamel is forming, the calcium salts are 
supplied by a rich plexus of blood-vessels now in direct contact 
with the cells of the stratum intermedium, all other portions of the 
enamel organ having disappeared from this part. Indeed, it is difficult 
to demonstrate clearly the cells of the stratum intermedium after any 

1 Dental Cosmos, February, 1896. 



THE ENAMEL ORGAN. 



67 



considerable portion of the enamel has been formed ; they appear to 

have been lost in the connective tissue which is everywhere above them. 

The origin of the enamel organs of the permanent teeth may be de- 

Fig. 48. 














Section of incisor of rat (X 175) : a, blood-vessels with corpuscles in situ; b, brunch of same de- 
scending to supply capillary loops about secreting papillse; c, ameloblasts. (Dr. J. Leon 
Williams' specimen.) 



scribed in general as follows : From the neck of the enamel organs of 
the twenty deciduous teeth, midway between the stratum Malpighii and 
the temporary enamel organ, growths in the form of buds are being 







Fig. 49. 










fiS 


| 


" 11 


1R 


cHBHHH 

"JBBI 


PM 




Section of incisor of rat (X 80) : a, capillary loops torn out of secreting papillse ; 5, secreting 
papillae after removal of capillary loops ; c, ameloblasts ; d, enamel ; e, dentin. (Dr. J. Leon 
Williams' specimen.) 

formed, increasing in length, and these result in the formation of the 
enamel organs of the permanent teeth, their grow r th taking place on 
the lingual surface of the temporary teeth. Soon after this, the tern- 



68 



EMBRYOLOGY OF THE DENTAL TISSUES. 

Fig. 50. 



>t 




mi 

Hi 



j 
1 



■& 



"""is 



f m< 






>yr 



^ 



Section of jaw, embryo of rabbit; permanent tooth seen developing under the temporary molar: 
1, enamel of temporary tooth ; 2, dental pulp ; 3, developing alveolar wall ; 4, permanent den- 
tin germ. (Section by Dr. Sudduth.) 



Fig. 51. 



Section of developing tooth of human embryo (X 1000) : a, large nucleated cells of middle layer 
(reticulum) of enamel organ ; b, stratum intermedium ; c, ameloblasts. (Dr. J. Leon Williams' 
specimen.) 



THE ENAMEL ORGAN. 



69 



porary enamel organ becomes separated from its cord. Between the 
temporary enamel organ and the permanent enamel bud, the cord 
of the temporary enamel organ is seen to be breaking up and losing 
its connection with the stratum Malpighii ; while the cord for the per- 

Fig. 52. 







Section of developing tooth, embryo of calf (X 1000) : a, b, nuclei of reticulum of enamel organ, 
showing spongiose character ; c, outer ameloblastic membrane ; d, inner ameloblastic mem- 
brane ; e,f, enamel globules faintly showing nuclear network. (Dr. J. Leon Williams' speci- 
men.) 

manent tooth appears as a continuation of the Malpighian end. The 
cord for the permanent incisor in the human embryo is formed about the 
fifth month, and while descending into the embryonic connective tissue 
assumes a spiral form of growth, as do the necks of most of the enamel 
organs of the permanent teeth, growing down to take their positions 
under the temporary teeth, where they go through all the changes that 



70 EMBRYOLOGY OF THE DENTAL TISSUES. 

have been spoken of in describing the growth of the temporary enamel 
organ. Dr. Sudduth says that as a rule the cords for the permanent 
molars arise directly from the epithelium of the mouth, that is, the 
Malpighian layer. Other authorities state that the first permanent molar 
only is from the Malpighian layer, as is the enamel organ of the tem- 
porary tooth. Bodecker is the author of the statement that all the 
permanent molar teeth are an offspring of the enamel organs of the 
second temporary molar tooth. The enamel organ of the second per- 
manent molar is an outgrowth from the first permanent molar ; the 
enamel organ of the third permanent molar being an outgrowth from 
that of the second. Von Brunn holds that the primary function of 
the enamel organ is that of determining the form of the future tooth. 
He goes so far as to assert that its calcification into enamel in some 
animals is a secondary function taken on later. In support of this 
opinion, he says that enamel organs are universal, even where no 
enamel is found. He holds that wherever dentin is to be found, there 
is an antecedent " form-building" investment of enamel organ. 

The Dentinal Papilla. 

The dentinal papilla, or, preferably, the dentin germ, has its 
origin in the embryonic connective tissue of the jaw. Sometime about 
the second month of fetal life, as the enamel organ of the first-forming 
teeth assumes its flask-like shape, and the cells within its central portion 
are seen to be differentiating, just under it is noticed an area of dense 
tissue, in shape somewhat like a crescent. It is distinctly outlined by 
its dense and active cell-multiplication. This is the first indication of 
the commencing growth of the dentin germ. As the enamel organ 
enlarges, and assumes the shape of a surrounding cap, a papilla-like 
growth takes place coincidently with it. About the ninth week it 
assumes the pointed form of the future incisor. With these changes the 
outer layer of the connective-tissue cells next the enamel cells will be 
found to have changed their form, and to have assumed a very distinct 
columnar appearance, forming a layer somewhat like the enamel cells, 
but broader. This layer has been falsely called a membrane, " mem- 
brana eboris" or membrane of the ivory. It is not a membrane, and 
all recent authorities ignore it as such. If the tissue has been carefully 
prepared, minute glistening bodies are seen, under the higher powers 
of the microscope, within the substance of the germ. These are calco- 
spherites, and are seen everywhere near the odontoblastic layer in the 
dentin germ, as well as in the enamel organ, near the enamel cells. 
They are mostly minute globules. Some are larger than others, caused 
undoubtedly by several merging together. They indicate that the 



THE DENTAL FOLLICLE. 71 

process of calcification is about to begin, and are constantly present 
while it is going on, throughout the process of the formation of the 
tooth. 

Dr. Sudduth is authority for the statement that there is no real 
union between the dentin germ and the enamel organ. There exists 
no intimate connection between the two surfaces other than that of per- 
fect adaptation to each other : vessels or nerves have never been dem- 
onstrated to pass from one to the other. The relation is analogous to 
that sustained by the epithelium and dermal layers of the mucous 
membrane of the oral cavity, from which they have their origin. 
Bodecker, on the other hand, states that there is a connection between 
the two. He says that when the enamel organ is detached from the 
papilla — as it frequently is, in sections — its outer surface appears beset 
with an extremely delicate fringe, the true connection between the pa- 
pilla and the enamel organ. 

The Dental Follicle. 

The walls of the dental sacculus have their origin in the area of 
tissue which is so plainly marked by its increasing growth, seen just 
under the enamel organ while in the shape of a flask. At this early stage 
are seen, from the outer edges of this area of tissue, encircling processes 
which, as the dentin germ forms, grow rapidly up, surrounding the 
enamel organ on all sides (see Fig. 53). Some authorities have stated 
that the dental sacculus does not wholly cover the enamel organ, but 
in the collection of the writer are specimens where its walls are seen 
to completely cover the dentin germ, so that it apparently is wholly 
enclosed. The bone of the jaw is now forming rapidly about it (mak- 
ing a nest, as it were, in which the sacculus and its contents, now 
the dental follicle, rest. The cells within the tissue of this sac are 
found to have separated by growth into two layers. They have not 
changed their form, but remain connective-tissue cells. The outer 
layer is seen to be much denser and very much more vascular than 
the inner one, and this is to form the dental periosteum ; the inner one 
is said to form the cementum of the root. 

This differentiation of a portion of the dental sac into a softer and 
looser tissue, but little firmer than that of the stellate reticulum of the 
enamel organ, has been thought by Magitot to be sufficiently pronounced 
to justify him in calling it a distinct organ, — the " cement organ." But 
the existence of such an organ is doubted by many authorities. Prof. 
Sudduth is of the opinion that the tissues of the sacculus do not arise 
wholly from the base of the dentin germ, but largely from a conden- 
sation of the fibrous connective tissue in which the enamel organ lies. 
The follicular wall just over the surface of the enamel organ is often- 



72 



EMBRYOLOGY OF THE DENTAL TISSUES. 



times found in folds. These have been called " papilliform eminences," 
and are seen to be projecting into or near the enamel cells. To this 
appearance some authors attach considerable importance, but it is 



Fig. 53. 




Section of jaw, embryo of pig, showing dental follicle: 1, dental follicle, consisting of enamel 
organ, dentin germ surrounded by the sacculus within the substance of the jaw ; 2, jaw-bone ; 
3, tongue ; 4, papillary layer of tongue. 



doubtful if it has any significance. It, like the folds in many other 
embryonic tissues, is to be taken up by the expansion of the part by 



growth. 



In regard to the cement organ , Tomes says : " In those creatures 
which have cementum upon the roots of the teeth only, no special cov- 
ered organ exists ; but osteoblasts, which calcify into cementum, are 
furnished by the tooth sac." 

The g-ubernaculum is a thin fibrous cord of dense tissue, connecting 
the permanent tooth follicle in its bony shell with the gum tissue just 
back of the neck of the corresponding temporary teeth. It is a struct- 
ure of no importance. 



CA L CIFICA TION. 73 

Calcification. 

Calcification is a process by which organic tissues become hardened 
bv a deposition of salts of calcium within their substance. In the intercel- 
lular tissue and in the substance of the cells themselves, these salts are 
deposited by the rich blood supply always near. They are deposited in 
minute particles and in such fine subdivisions as to make it difficult 
to demonstrate many of them even with the higher powers of the mi- 
croscope. The intercellular substance, either a protoplasmic or gelati- 
nous fluid or semifluid, contains the calcium particles. In it they change 
their nature chemically, uniting with the albuminous organic substance 
of the part, and form small globular bodies which have been called 
calco-spherites ; and these, blending or coalescing at the point of cal- 
cification, form a substance called calco-globulin. This calco-globulin, 
which is a lifeless matter, has been deposited through the cells into the 
gelatinous substauce, where, by a further hardening process, it becomes 
the fully calcified matrix. 

Mr. Rainey, and later Prof. Harting and Dr. Ord, have devoted 
much time to the study of this substance. Mr. Rainey found that if 
a soluble salt of calcium be slowly mixed with another solution capable 
of precipitating it, the resultant calcium salt will go down as an amor- 
phous powder, and sometimes as minute crystals. But when the cal- 
cium salts are precipitated in gelatin, the character of the calcium salts 
is materially altered. Instead of a powder, there were found various 
curious, but definite, forms quite unlike the crystals or powder produced 
without the intervention of the organic substance. Mr. Rainey found 
that if calcium carbonate be slowly formed in a thick solution of albu- 
min, the resultant salt has changed in character ; it is uoav in the form 
of globules, laminated, like tiny onions, which coalesce into a laminated 
mass. In this Mr. Rainey claims to find the clue for the explanation 
of the development of shells, teeth, and bone. 

At a more recent date, Prof. Harting took up this line of investiga- 
tion and found that other calcium salts would behave in a similar man- 
ner. The most important addition to our knowledge made by Prof. 
Harting lay in the very peculiar constitution of the " ealco-spherite," 
by which name he designated the minute globular forms seen and 
described by Rainey. Mr. Rainey found that albumin actually en- 
tered into the composition of the globule, since it retained its form 
even after the action of acids. Prof. Harting has shown that the 
albumin left behind after treatment of a calco-spherite with acid is 
no longer ordinary albumin ; it is profoundly modified, becoming 
exceedingly resistant to the action of acids. For this modified albu- 
min he proposes the name " calco-globulin." Microscopic glistening 



74 



EMBRYOLOGY OF THE DENTAL TISSUES. 



globules like those described above are constantly seen at the edges 
of tissue where enamel, cementum, dentin, or bone are to be formed 
or are forming. Robin and Magitot have described isolated spherules 
of calcium salts as occurring abundantly in the young pulps of human 
teeth, as well as those of other animals, and Tomes suggests that per- 
haps all deposits of calcium salts commence in this way. These micro- 
scopic globular bodies are calco-spherites. 

CALCIFICATION OF THE DENTIN. 

Although the enamel organ is first formed, with its layer of amelo- 
blasts all ready to commence the process of calcification, it is at the 
tip and within the substance of the dentin germ where this process 
really begins. The papilla has assumed the form of the point of the 
future tooth crown ; the cells everywhere upon its outer surface — the 

Fig. 54. 



H>$ h 







mmm 




Section of growing tooth of calf at birth, showing the layer of odontoblasts and fibril cells 
attached to the forming dentin. 



odontoblastic layer — are found to be actively at work forming the first 
cap of dentin. They are seen to be imbedded in a transparent and 
structureless gelatinous substance, in which small globular masses are 
already forming. The cells are clearly defined, being somewhat broader 
than the ameloblasts just above them, and like them are seen to be in a 
single layer, which has been named the " membrana eboris," but it is 
not a true membrane (see Figs. 55 and 56). The cells are found to vary 
in form, according as the formation of the dentin is actively going on 
or not. During the period of their greatest activity they are broad at 
the end directed toward the dentin cap, so as to look almost abruptly 
truncated, having as many as three or four, in some instances as many 
as six, dentinal processes proceeding from a single cell, Boll having 
counted as many as six. The cells are finely granular, and are, accord- 
ing to Waldeyer and Boll, destitute of membranes. The nucleus is 



CALCIFICATION. 



75 



oval and lies in that part of the tell farthest from the dentin, and is 
sometimes prolonged toward the dentinal processes so as to be ovoid 
or almost pointed. The dentinal process passes into the canals of the 




■ 




Section of developing tooth, embryo of pig : 
1, stellate reticulum of enamel organ ; 2, 
stratum intermedium; 3, internal epithe- 
lium of enamel organ (ameloblasts); 4, 
forming odontoblasts ; 5, pulp tissue. 



Fig. 56. 




Section of jaw, embryo of pig : 1, ameloblasts 
showing Tomes' processes : 2, layer of formed 
dentin ; 3, odontoblasts ; 4, pulp tissue. (Sec- 
tion by Dr. Sudduth.) 



dentin, and it frequently happens that the layer of odontoblasts is 
slightly separated from the dentin in making a section, when these 
processes, which constitute the dentinal fibrils, may be seen stretching 
across the interval in great numbers. Intermediate between the per- 
manently soft central fibrils and the general calcified matrix is that 
portion which immediately surrounds the fibril, namely, the dentinal 
sheath. 

In 1891 Mr. Mummery noted, as the dentin was forming, the 
appearance of connective-tissue fibers, or bundles of fibers, just in ad- 
vance of the main line of calcification. Their high refractive index 
suggested their partial calcification, the processes being continuous from 
the formed dentin to the general connective tissue of the dentin germ. 
He found in a young developing tooth a distinct reticulum of fine fibers 
passing between and enveloping the odontoblasts. By careful focussing, 
lie saw these fibers gathered into bundles and incorporated with the 
matrix substance of the dentin, out of which they seemed to spring. 
The origin of these fibers seems to be from connective-tissue cells, which 
are found everywhere in the formative pulp next the odontoblastic layer, 
and also, as he has demonstrated, between the odontoblasts themselves. 
These fibers are the scaffolding on which the tooth matrix is built up ; 
they are incorporated in the matrix of the dentin, and form really the 
basis of its substance. 



76 EMBRYOLOGY OF THE DENTAL TISSUES. 

The odontoblasts are modified connective-tissue cells that superin- 
tend the deposition of the calcific material which is to form the calcified 
matrix. The thickening of the dentin is by successive deposits of this 
material in the form of layers which calcify. Fibrils from the odonto- 
blasts remain within the formed and forming dentin as the persistent 
organic contents of the canals. This forming of the dentin is at the 
expense of the dentin germ, which is thus gradually reduced until it 
becomes, when the tooth is fully formed, its pulp. Thus it is seen that 
dentin is a secretion in the form of calcific material coming from the 
abundant blood supply in the pulp tissue near the odontoblasts. The 
material is given out from the cells in a globular form (calco-spherites) 
into a protoplasmic fluid, or semifluid, found everywhere against the 
calcifying dentin. In this substance is the scaffolding of fine con- 
nective-tissue fibers spoken of by Mr. Mummery, of London. The 
calco-spherites meeting against the formed dentin coalesce into a 
layer of calco-globulin, and this, becoming fully calcified, forms an 
additional layer of dentin, and the process continues until the tooth 
is formed. 

By the deposition of calcium salts into the protoplasmic layer calco- 
globulin is formed, and by its calcification the dentin tissue becomes a 
homogeneous mass, penetrated by many parallel canals filled with the 
persistent dentinal fibrils. Beside these parallel canals with their 
fibrillar contents many lateral canals are seen branching off from the 
main canals and anastomosing with neighboring canals. 

Exceptions may be taken to many of the statements of histologists 
in this field ; many or most mistakes are traceable to faulty methods 
of technique. Processes which involve the securing of specimens 
while they are yet warm are greatly preferable. These are placed in 
a quarter of one per cent, to one-half of one per cent, solution of 
chromic acid, which is changed several times a day, for three or four 
days. At the end of this time the edges of the dentin which were 
calcified are found to be sufficiently softened to make a number of 
sections. The teeth are then taken from the acid solution, washed in 
distilled water, placed in a solution of gum arabic for several hours, and 
next transferred to a solution of alcohol to abstract the water. Paraffin 
and lard are melted together and poured into a convenient mould. 
When this clouds in the process of cooling, the tooth, which has had its 
outer surface dried as much as possible with bibulous paper, is placed in 
it and the whole allowed to cool. The microtome for this purpose should 
permit the immersion of both tissue and knife when the sections are 
cut. These sections float off in the fluid, and remain there until used. 
Sections are cut until the calcified tissue is reached. The sections 
are placed in distilled water for a few minutes to dissolve out the 



CALCIFICATION. 



77 



gum, and then mounted in glycerin jelly. The difference in the 
appearance in the tissue prepared by this method is marked. It is 
seldom necessary to stain tissues which are to be studied under the 
higher powers of the microscope. 

The dentin matrix is mainly a connective-tissue calcification, and 
it should be remembered in examining sections of forming dentin that 

Fig. 57. 



v. 



I 



I 



Section of growing tooth of calf at birth, showing the formed dentin, the layer of calco-globulin 
and two odontoblasts ; a fibril is seen at the side of one of thern. 

sections are seen at that stage of growth at which the death of the 
part left it. In some the odontoblasts are seen square and abrupt against 
the calcified matrix, having no appearance of other tissue between them. 

Fig. 58. 




Section of growing tooth of calf at birth, showing the layer of odontoblasts square and abrupt 
against the forming dentin; some of the fibril cells, or dentin corpuscles, that are pear- 
shaped, are seen running between them. 



In others the odontoblasts are seen square and abrupt against a layer 
■of a fibrous, gelatinous tissue, which is seen to be filling with globular 



78 



EMBRYOLOGY OF THE DENTAL TISSUES. 



masses (Fig. 57). This layer is between the odontoblasts and the cal- 
cified matrix. A section from another embryo will show a different 
picture. Here is seen a layer of mostly pear-shaped cells, not quite 
against the calcified matrix, showing their fibrils drawn out and run- 
ning into the canals of the matrix (Fig. 58). There is no appearance 
of a gelatinous layer, while here and there against the calcified matrix 
are what appear to be used-up odontoblasts, only portions of them 
showing. The cells in this picture rarely show more than one fibril 
running into the canals of the matrix. Again, a section from another 
tooth will show layers of calco-globulin merging together and forming a 
new layer of the matrix, and, in this, parts of the odontoblasts seem to 
lose their identity (Figs. 59-61). An important fact not to be lost sight 

Fig. 59. 




Section of developing tooth of calf at birth : cross section showing first-forming layer of dentin 
matrix. The calco-spherites are seen forming a layer of calco-globulin which by further calci- 
fication is to become the matrix. 



of is that all of these appearances indicate the different stages in the 
growth of the dentin matrix. Conclusions cannot be drawn from any 
one of them, so all must be studied. These appearances are not found 
at the early stages alone ; they are also seen when the matrix is nearly 
formed. 

The odontoblasts are masses of protoplasm without membranes, and 
are at a certain stage of growth square and abrupt against the matrix 
(Fig. 58). It is an easy matter to find among them, and immediately 
adjacent, large numbers of pear-shaped cells, tapering into the dentinal 
fibril. The odontoblasts, when calcification is active, are scarcely 
more than masses of protoplasm, filled with minute globules (Fig. 62). 
The fibrils which appear to come from them, described by Tomes as 
pulp, lateral, and dentin processes, originate probably from a fibril- 



CALCIFICATION. 
Fig. 60. 



79 







n 


r\ 


■ 

j 

■ j 'i -.■■'!> - 


r I 


\ . 










*ir*"% 


t 


■ 




\ 1 i \*V\ a i 












i\ 1 / v v f 

_ i _ i V 




\ 



Section of growing tooth of calf at birth, showing fibrils, fibril cells and odontoblasts ; also the 
layer of calco-globulin and the forming dentin. 



Fig. 61. 



I 









t &i 







s V*V f V4Y; 



Section of growing tooth of calf at birth, showing fibrils, fibril cells, and odontoblasts. The pulp, 
has been teased away, leaving these cells clinging to the formed dentin. 



Fro. 62. 



i JLM;- A* 



Ml 




Section of growing tooth of calf at birth, showing odontoblasts and fibril cells. 



80 



EMBRYOLOGY OF THE DENTAL TISSUES. 



forming cell. These pass through the soft substance of the odonto- 
blasts (protoplasm) and seem to be a part of them, but in fresh, young 
sections the so-called processes move in the substance of the odonto- 
blasts by pressure on the cover-glass, and the fibril may be traced to 
a pear-shaped cell beyond (Fig. 62). There will usually be found as 
many processes going out from sides or ends of the odontoblasts toward 
the pulp as there are going into the matrix from the dentin end of the 
cell. In cross sections of the odontoblasts, delicate light spots are seen 
in the substance, which are probably the cut fibers. When the layer 
of odontoblasts is teased away from the forming dentin, fibrils are seen 
bridging the gap, apparently offshoots from the odontoblasts ; but on 
careful examination there will usually be found a decided line of demar- 
cation across the fiber at the point where it meets the square end of the 






Fig. 63. 




Section of growing tooth of calf at birth; odontoblasts that were square and abrupt against the 
forming dentin, showing the line of demarcation between the cell and the fibril. They are 
attached to the pulp. 



odontoblast (Fig. 63). This line seems to show that the fibril was not 
continuous with the protoplasm of the cell. Other sections which have 
been separated by teasing, show odontoblasts having their side masses 
of protoplasm drawn away from the fibril which apparently has run 
through it. Some of this protoplasm is left upon the fibril, giving it 
a ragged appearance as it passes from a canal in the matrix across to 
the separated pulp tissue, bridging the gap. 

The pear-shaped cell has perhaps a more important function than 
the odontoblast proper. It is to supply the life and nourishment to 
the whole of the calcified matrix, as the bone corpuscle within its 
lacuna supplies life and nourishment to bone and cementum. 

Minute calcium globules or calco-spherites are seen to be arranging 
themselves against the already formed matrix, where they collect in large 



CALCIFICATION. 



81 



Fig. 64. 




Section of human tooth, showing globules of calco-globulin which have been deposited in the 
gelatinous layer by the odontoblasts ; these have been pulled away in making the section. 
(Section by Mr. Mummery.) 



Fig. 65. 



ig. m. 





Frc. 6/ 







Sections of growing tooth of calf at birth, showing formation of layer of masses of calco-globulin 

to form layer of dentin. 



82 



EMBRYOLOGY OF THE DENTAL TISSUES. 



numbers, and lose their individuality by merging into one another, form- 
ing larger globules, of various shapes and sizes (Fig. 64), seeming to 
take into their substance portions of the odontoblast. These globules 
enlarge until they reach their typal width, expand laterally, meeting 
and coalescing with others. The minute globules are seen within the 
odontoblasts of different sizes, all having a glistening appearance, some- 
thing like fat globules in cells. The early layers formed by the glob- 
ules are about the width of the band of formative cells. (See Figs. 
65, 6Q y 67). 

CALCIFICATION OF THE ENAMEL. 

The statement made by Tomes and others that enamel is formed 
by the actual conversion of the enamel cells into the enamel rods is an 
erroneous one. The enamel cell does not calcify ; it superintends the 
laying down of calcific material which is to form the rod. For the 
earliest deposit of enamel the calcium salts are stored in the meshes 
of the so-called stellate reticulum, and as the first enamel forms, the 
enamel organ proper disappears at this point. Only the two inner- 
most layers remain ; these are the layer of the columnar cells (amelo- 
blasts) over the forming enamel, and a layer of cells somewhat resem- 
bling connective-tissue cells (the stratum intermedium) over these. The 

two layers are separated by what 
appears to be a line of tissue which 
has been called a membrane. The 
embryonic connective tissue of the 
jaw is now in direct communication 
with the stratum intermedium, and 
a rich blood supply is developing 
near the point of juncture. The 
function of the cells of the stratum 
intermedium is supposed to be the 
supplying of new cells to the amelo- 
blastic layer as they may be needed by 
the increase in the circumference of 
the enamel, as new enamel is formed ; 
to furnish the organic fluid in which 
the calcium salts are deposited ; 
and to supply the fine network of 
fibers, the scaffolding upon which 
the enamel rods are to be built. Prof. Sudduth is the authority for 
the statement that enamel is nothing more or less than a coat of mail 
supplied by Nature to protect the dentin. 

Enamel cells that have been properly prepared and not shrunken 
will be seen filled with minute globules. The authorities who speak of 



Fig. 68. 



Section of human developing tooth, showing 
calcification of enamel : 1, globules of cal- 
co-globulin deposited on dentin cusps 
from the enamel cells ; 2, dentin (the 
enamel cells have been cut away in prepar- 
ing the section). 



CALCIFICATION. 



83 



granules of calcium salts have described them as seen in the shrunken 
cells in the tissue as it is usually prepared. They are really globular, 
though minute. If, just as calcification commences, a few drops of 
dilute nitric acid be placed on the slide near the edge of the cover- 
glass, the liquid will, by capillary attraction, run under, and these re- 
fractive granular bodies in the stellate reticulum will disappear, as will 



Fig. 69. 



Fig. 70. 





Mm 




Sections from growing tooth of calf at birth, showing how enamel rods are formed from the globu- 
lar masses of calco-globulin. 



Fig. 71. 



M 




Same as Figs. 69 and 70. 



those that are in the enamel cells themselves. Large numbers of small 
bubbles will accumulate, and force themselves out from under the cover- 
glass. This would seem a positive demonstration of the presence, in the 
stellate reticulum and enamel cells, of calcium carbonate just previous 
to commencing calcification. In teasing off portions of active enamel 
cells, we find the surface of the dentin on which it is being formed 
covered with layers of globules that have been deposited there by the 



84 



EMBRYOLOGY OF THE DENTAL TISSUES. 



Fig. 




enamel cells (Fig. 68). These, given out from the cell continually, 
form the enamel rods. One rod is separated from another by a proto- 
plasmic cement substance. 

Dr. Graf Spee says that when the tissue is properly prepared — and 
he lays great stress on this point — at the time of the formation of the 
enamel, the globules are always to be found. Their entire absence at 

earlier stages is an indication that 
these globules are an enamel sub- 
stance. He gives to them the name 
" enamel drops," and says he saw 
these "enamel drops," when enamel 
3 is to be formed, appear only in the 
half of the enamel cells which rests 
j on the dentin ; afterward they were 
to be seen farther up in the cell, but 
not quite to the region of its nucleus. 
Many of them were so small as to be 
scarcely measurable, and they are al- 
■' —.!._' ..;.;...'.".'.- ways spherical. Great numbers of 

section of developing tooth of caif at birth, t ^ em are co n ec t e d at the periphery, 

showing first-forming layer of enamel. ' The . -i i 

globules of caico-giobuiin are seen arranged and appear here either to be completely 

in lines where rods are to be formed: 1, merRed or to fuse Wether. The 

enamel cells containing calco-spherites ; 2, . & & 

globules arranged to form rods; 3, first- lower part of the Cell contains the 

orming ayer o ename , 4, entm. larger " enamel drops," which merge 

without sharp boundaries into the substance of the enamel rods. This 
then appears as a part of the enamel cell, in which the originally iso- 
lated " enamel drops " have run together into a continuous mass, and 
the growth of the enamel rod, once begun, appears to take place by the 
addition of new " enamel drops." 

The minute globular forms described by Dr. Spee are calco-spherites ; 
the larger ones, his " enamel drops," are globules of calco-globulin which 
are to form the rods (Fig. 72). 

Appearances of calcined fibers projecting beyond the line of calci- 
fication are seen when studying sections of forming young enamel, and 
these are evidences that fine processes of fibers from the cells of the 
stratum intermedium pass down through and among the ameloblasts to 
the forming enamel beneath. These are probably the processes which 
Mr. Tomes saw and described as connecting the enamel cells with the 
stratum intermedium. If one separates slightly the enamel cells from 
the stratum intermedium the parted cells will have the appearance of 
broken processes or fibers, and we may be able to see fibers crossing 
from the enamel cells to the stratum intermedium. 

A longitudinal section of a human tooth at birth, just after the 



CALCIFICATION. 85 

process of calcification in the enamel has begun, will show, between 
the enamel cells and the formed enamel, a thin layer which has been 
called, by earlier investigators, the membrana prceformativa. It was 
misunderstood then : it is not a membrane. It is the latest deposition 
of enamel from the enamel cells, composed of globules or masses of 
calco-globulin ; and around these globules there seems to be a fibrous 
network. Connecting with this fibrous network, and running to the 
formed enamel beneath, are innumerable thread-like processes, in ap- 
pearance like fibers. There are indications of fibers which have been 
broken on the upper portion of this thin layer ; these appear as 
though they had been broken off in the separation of the layer from 
the enamel cells. In a longitudinal section of the tooth of a calf at 
birth, when the recently formed layer of enamel is still in contact with 
the fully calcified enamel, this younger portion may be teased off, 
exposing to view what appear to be fibrils standing out from the sur- 
face. These have apparently been drawn out from the only partially 
calcified new tissue. In other sections this appearance is more marked. 
They may appear so large that it is probable they have been enlarged 
either by the action of reagents or by calcific matter clinging to a 
fiber, if one is there, and they are undoubtedly partially calcified. 
They are very much coarser than the fine fibrils seen between the 
enamel cells. Deeper within, these processes are seen to surround the 
globules or masses which have been deposited by the enamel cells, and 
which are forming the rods. In other sections from the tooth of the calf 
the younger layer of forming enamel shows a network of fibers ; they 
are surrounding the recent deposition of globules. It is only in this 
layer that this appearance is clearly shown ; this network in more 
fully formed enamel cannot be seen, yet a distinct network is always 
visible in the layer first deposited. It is probable that these pro- 
cesses have their origin among the cells of the stratum intermedium ; 
that they pass either within or between the enamel cells, and thus on, 
to form a very fine fibrous substructure, throughout which are deposited 
the globules which are to form the future enamel rods. When the cal- 
cification of the rod is complete, the calcium salts have been so densely 
deposited as to entirely obscure the appearance of any fiber. 

To sum up : there probably exists in developing enamel, as has 
already been found in developing bone and dentin, a fibrous sub- 
structure on and throughout which the enamel globules are deposited. 
After the enamel is wholly formed, this structure seems to be wholly 
blotted out in the dense calcification of the tissue (Figs. 73, 74). In 
sections of completely formed enamel the writer has been unable to 
trace it, although the methods of those who claim to have seen it 
have been faithfully followed. In regard to a protoplasmic reticulum 



86 



EMBRYOLOGY OF THE DENTAL TISSUES. 
Fig. 73. Fig. 74. 









Sections of very young enamel (human), showing the appearance of a fibrous structure : 1, enamel 
cells ; 2, newly forming enamel ; 3, dentin. 

of living matter in formed enamel, it is undemonstrable. Klein states 
that it is improbable that nucleated protoplasmic masses are contained 
in the interstitial substance of the enamel of a fully formed tooth. 



CALCIFICATION OF THE CEMENTUM. 

In the year 1858, Magitot, a French histologist, claimed to have 
found within the follicle of a developing tooth a special organ for the 
development of the cementum. In 1861 Robin and Magitot made a 
presentation of the same facts. With the exception of these authors, 
no other authority has recognized the presence of this special organ ; 
while Kolliker, Waldeyer, Herz, and others had formerly denied its 
existence. Although there are appearances, in a fully formed follicle, 
of a tissue between the calcifying dentin germ and the outer covering 
of the sacculus, which might admit of the supposition of the existence 
of such an organ, it cannot be traced with certainty. The appearance 
may be noted in sections from embryos of the pig and calf. At a later 
stage when the crown is further developed there are also to be seen 
infoldings of the tissue at the base of the germ which may develop 
into a special organ for the formation of the cementum, as stated by 
Magitot ; but in teeth more matured, where the cementum has already 
commenced its growth, there are no indications of a special organ. 

If the developing tooth is examined just after the cementum has 
begun to form, its matrix will be found to be made up of masses 
looking like scales of a tissue found everywhere on the borderland of 
calcification. It is calco-globulin, and has been formed from globules. 
At this early stage the calcific material is in the osteoblasts, and is 
given from them to the dentin, where a thin layer is forming. The 



THE DENTAL PULP. 87 

osteoblasts are filled with minute, glistening globules. As the growth 
continues, these cells appear to fuse into the cementum already formed. 
At the neck of the tooth outside this layer, which is forming the matrix 
of the cementum, a row of cells is seen which, according to Roller, re- 
sembles an epithelium. They are really new osteoblasts or cemento- 
blasts filled with the minute glistening bodies. Just exterior to these 
cells, roundish nucleated cells with innumerable processes are seen 
slightly resembling a stellate reticulum. Outside of these is a con- 
nective-tissue layer which will become the periosteum. This slight 
amount of stellate tissue is probably what has been called the special 
cement organ. Across the developing matrix of the cement are found 
numerous connective-tissue fibers seen and described by Sharpey and 
named after him Sharpey' s fibers. They become calcified within the 
matrix. As the cementum grows thicker we find infolded within its 
substance nucleated bodies which appear to be connective-tissue cells. 
They appear larger than the osteoblasts and are forming the regular 
lacunae of the cementum. Their function is to give nourishment to 
the matrix of the cementum, anastomosing with one another by means 
of many fine canals, many of which run in the direction of the termi- 
nation of the dentinal canals as though connecting with them. They 
are not as regular as those in true bone, and are often very much larger. 
The processes of these cells anastomose with the dentinal canals through 
the interglobular spaces of the so-called granular layer of Tomes. Thus 
the matrix of the cementum is formed from the cementoblasts which 
have become filled with calcific material from the blood supply every- 
where near. They rest against already formed dentin and become 
merged into a layer of calco-globulin, which in turn becomes calcified 
into the first layer of cementum. Layer after layer is formed, and 
this gives to the cement the peculiar laminated appearance so often 
seen in it. 

The Dental Pulp. 

The tooth pulp is that which remains of the dentin germ after cal- 
cification is completed. It is very generally but erroneously called the 
" nerve." In the young tooth it is composed of connective-tissue matrix 
which contains the nerves and vessels supplying the dentin. These 
are more numerous near the odontoblastic layer, the nerve fibers appear- 
ing to terminate here. The odontoblasts cover the surface of pulp like 
an epithelium. Just within these is a layer of cells consisting of a 
comparatively pale and transparent zone, and this has been called the 
basal layer of Weil. It is described as consisting of fine connective- 
tissue fibrils which communicate with the processes of the odontoblasts. 
Von Ebner doubts the existence of this layer, as does Rose. 



88 



EMBRYOLOGY OF THE DENTAL TISSUES. 















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CHRONOLOGY OF TOOTH DEVELOPMENT. 



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90 EMBRYOLOGY OF THE DENTAL TISSUES. 

In a recent paper on the Histology of the Pulp, by Erwin Hoehl, he 
states that the cells of the pulp show in the different life periods cha- 
racteristic differences in form and number. Three kinds are found, 
which arise from one another by metamorphosis in the following way : 
(1) Round cells with large nucleus and scanty protoplasm. (2) Irregu- 
larly shaped cells with many freely anastomosing processes. (3) Spindle- 
shaped cells with the same character as the foregoing. The changes of 
the cell form begin at the periphery and proceed toward the centre of 
the pulp. The outermost peripheral layer of the branched cells contains 
the elementary or primary odontoblasts. Central ward from these is a cell 
layer which, with reference to the function of its elements, is called the 
conjugation cell layer. The secondary odontoblasts arise by conjugation 
of the primary odontoblasts with the conjugation cells, and they form 
the dentin. The conjugation processes probably cease only with the 
completion of growth in the tooth. 

Of the peripheral processes of the primary odontoblasts the larger 
one represents what will be the future dentin fibril. The increase of 
cells seems to be dependent upon the development of the capillaries, 
inasmuch as more cells are found where the distribution of capillaries is 
most dense, i. e. on the periphery of the pulp. The gradual decrease 
of the number of branch cells in the centre of the pulp during the 
course of development is because only trunk vessels are found here* 
In the place of these destroyed cells we find a delicate cellular network 
which is probably derived from the numerous anastomoses of the cell 
processes. Next to or just within the odontoblastic layer is seen a bright 
zone variable in width ; this is the so-called WeiVs layer. Between this 
and the fibrous or central portion of the pulp is an intermediate layer 
which forms a contrast with the delicate fibrous elements of Weil's layer, 
and in this way WeiPs layer is made visible. 

The ground substance of the pulp by a certain method of treatment 
shows a dense interlacing of fibrillar which are arranged parallel to one 
another and seem to run in the direction of the axis of the tooth. 

The Gum. 

Gum tissue is the same as that of the general mucous membrane of 
the mouth. It is more dense because it is bound down to the bone 
by numerous fibers of its own, and it is also united with the periosteal 
tissue which spreads into it in every direction. Numerous large single 
and compound papilla? are seen. The blood supply is abundant, but 
nerve tissue is not often found. The histological appearances which 
look like young enamel organs are the glands of Serres. Near develop- 
ing teeth epithelial clusters are frequently seen, the remains of the dis- 
appearing necks of the enamel organs. The cells of the stratum Mai- 



THE PERICEMENTUM OB ALVEOLO-DENTAL MEMBRANE. 91 

pighii of the epithelium are seen to be in columns, and from these 
new cells are formed, which flatten and lose their vitality as they 
near the outer surface, where they are given off as lifeless scales. 

The Pericementum or Alveolo-dental, Membrane. 

This is a formation of fibrous connective tissue, having its origin 
from the outer layer of the sacculus (Fig. 75). It differs from the gum 
tissue in that it is not so dense. Tomes speak of it as having a rich 
supply of nerve fibers. 



■MB 



Fig. 75. 



;~;v 




Alveolar dental membrane (sect 



lembrane ; 2, bone 



if alveolus ; 



The pericementum passes into the gum at the tooth neck, where it is 
thicker than at any other part. It is seen to be everywhere connected 
with the periosteal membrane of the alveolar process. The general 
direction of its fibers is across, slightly wavy, downward from the 
alveolus to the tooth root. In the young tooth there are no breaks in 
the continuity. There is no appearance of two separate membranes, 
one for the root and the other for the alveolus ; but simply a mem- 
brane common to both surfaces. 



92 EMBRYOLOGY OF THE DENTAL TISSUES. 

The pericementum forms an elastic membrane and acts as a cushion 
to lessen the concussion when the teeth come together during mastica- 
tion. Its connective-tissue fibers are seen to pass into the cementum, 
and within that substance are supposed to be Sharpey's fibers. Where 
the cementum is thicker it is rich in cellular structure. TKe pericemen- 
tum, then, connects with the cementum by its fibers; these in turn con- 
nect with the branches of the cement corpuscles, through these with the 
granular layer of Tomes, and thence on to the fibrils of the dentin. 

Nasmyth's Membrane. 

Concerning this structure Tomes states that — 

" Under the name of Nasmyth's membrane, enamel cuticle, or per- 
sistent dental capsule, a structure is described about which much differ- 
ence of opinion has been, and indeed still is, expressed. Over the 
enamel of the crown of human or other mammalian teeth, the crown of 
which is not coated by a thick layer of cementum, there is an exceed- 
ingly thin membrane, the existence of which can only be demonstrated 
by the use of acids, which causes it to become detached from the surface 
of the enamel. When thus isolated it is found to form a continuous 
transparent sheet, upon which, by staining with nitrate of silver, a 
reticulated pattern may be brought out, as though it were made up of 
epithelial cells. The inner surface of Nasmyth's membrane is, however, 
pitted for the reception of the ends of the enamel prisms, which may 
have something to do with this reticulate appearance. It is exceedingly 
thin, Kolliker attributing to it a thickness of only one twenty-thousandth 
of an inch. But, nevertheless, it is very indestructible, resisting the 
action of strong nitric or hydrochloric acid, and only swelling slightly 
when boiled in caustic potash. Notwithstanding, however, that it resists 
the action of chemicals, it is not so hard as the enamel, and becomes 
worn off tolerably speedily, so that, to see it well, a young and unworn 
tooth should be selected." 

The writer's investigations lead to the inference that the membrane 
is nothing more than the layer of cells of the internal epithelium of the 
enamel organ, the ameloblasts, which, having performed their function, 
have filled with calco-globulin and have partially calcified, becoming 
somewhat like that tissue which we find on the borderland of calci- 
fication. 

It is probable that the lacunae found occupying a fissure between 
the cusps of the teeth, in the enamel, are nothing more than a little of 
the connective tissue which has become infolded and ossified before 
the eruption of the tooth. 



CHAPTER III. 

DENTAL HISTOLOGY WITH REFERENCE TO OPERATIVE 

DENTISTRY. 1 

By Frederick B. Noyes, B. A., D. D. S. 



The development of our knowledge of the cell has had a most pro- 
found effect upon the entire practice of medicine ; in fact, the progress of 
modern medicine dates from the studies of cell biology, the germ theory of 
disease being only one of the phases of this development. In terms of the 
cell theory the functions of the body are but the manifest expression of 
the activities of thousands or millions of more or less independent but 
correlated centres of activity : if these centres or cells perform their 
functions correctly, the functions of the body are normal ; but if they 
fail to perform their office, or work abnormally, the functions of the 
body are perverted. In the last analysis, then, all physiology is cell 
physiology ; all pathology cell pathology. To modern medicine his- 
tology, or the cell structure of the organs and tissues of the body, 
together with cell physiology, is the rational foundation of all practice. 
This is as true for the dentist as for the physician so far as regards all 
of the soft tissues of the mouth and teeth that he is called upon to 
treat and handle. With caries of the teeth, the disease which most 
demands the attention of the dentist, the case is somewhat different. 
Caries of the teeth is an active destruction, by outside agencies, of 
formed materials which are the result of cell activity (the tissues them- 
selves being passive). The cellular activities of organs and tissues of 
the body may have an influence, but this is only in producing those 
conditions of environment which render the activities of the destructive 
agents efficient in their action upon tooth tissues. Though the enamel 
and dentin are passive, we can understand the phenomena of caries 
only as we understand the structure of the tissues ; and not only 
must the treatment of caries be based upon a knowledge of the 
structure of the tissues, but the mechanical execution of the treatment 
is facilitated by that knowledge. In the preparation of cavities the 
arrangement of the enamel wall is determined by our knowledge of 
the direction of enamel prisms in that locality, and to a certain extent 

1 In the preparation of this material I am indebted to Dr. G. V. Black for the use of 
his large and valuable collection of microscopic slides, and for much advice and many 

suggestions. 

93 



94 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



the position of the cavity margins must be governed by our knowledge 
of the structure of the enamel. In the execution of the work a minute 
knowledge of the direction of enamel rods becomes the most important 
element in rapidity and success of operation. 

From the standpoint of comparative anatomy, the teeth are found 
to be not a part of the osseous system, but appendages of the skin, 
and are to be compared with such structures in the body as the nails 
and the hair. The teeth are a part of the exo-skeleton, and their rela- 
tion to the bones of the endo-skeleton is entirely secondary, for the pur- 
pose of strength, the bone growing up around the tooth to support it. 

If we examine the skin of such an animal as the shark, we find 
the entire surface covered with small calcified bodies which are really 

Fig. 76. 







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Shark's skull (Lamna cornubica), showing succession of teeth. 



small simple cone-shaped teeth. The mouth cavity is to be regarded, 
when viewed in the light of its development, as a part of the outside 
surface of the body which has been inclosed by the development of the 
neighboring parts, and the dermal scales or rudimentary teeth which 
were found in the skin covering the arches which form the jaws have 
undergone special development for the purposes of seizing and masti- 
cating the food. In the simplest forms there is only a development 
in size and shape of these scales, and they are supported only by the 
connective tissue which underlies the skin. These teeth are easily torn 
oif in the attempt to hold a resisting prey, and, as in the shark, they are 
constantly being replaced by new ones (Fig. 76). In the more highly de- 
veloped forms there is a growth of the bone of the arch forming the jaw 



DENTAL TISSUES. 



95 



upward around the bases of these scale-like teeth, to support them 
more firmly and render them more useful. 

If we compare the structure of the hair with that of the tooth, we 
find in the case of the hair a horny structure formed by epithelial 
cells resting upon a papilla of connective tissue ; in the case of the 
tooth, a calcified structure formed by epithelial cells resting upon a 
papilla of connective tissue which is also partially calcified. 

The relation of the bones of the jaws to the teeth is entirely a secondary 
and transient one. The bone grows up around the roots of the teeth to 

Fig. 77. 



tym "^m 




Changes in the mandible with age ; buccal and lingual view. 

support them, and is destroyed and removed with the loss of the teeth 
or the cessation of their function. In this way the development of the 
alveolar process takes place around the temporary teeth ; all of this bone 
surrounding their roots is absorbed and removed with the loss of the 
temporary dentition, and a new alveolar process grows up around the 
roots of the permanent teeth as they are formed. This development of 
bone around the roots of the teeth leads to the changes in the shape of 
the body of the lower jaw, increasing the thickness above the mental 
foramen and the inferior dental canal. When the teeth are finally lost 
this bone is again removed and the body of the jaw is reduced in thick- 
ness from above downward (Fig. 77). These phenomena are of im- 
portance in their bearing upon the causes and treatment of diseased con- 



96 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

ditions of the teeth, particularly those which involve the supporting 
tissues. 

Dental Tissues. — The human teeth are made up of four tissues 
(Fig. 78) : 

1. The enamel covers the exposed portion of the tooth, or crown, 
and gives the detail of crown form. Its function is to protect the tooth 
against the wear of friction. 

2. The dentin forms the mass of the tooth and determines its class 
form, the number of cusps and the number of roots being indicated by 
the dentin form. 

3. Cementum covers the dentin beyond the border of the enamel, 
overlapping it slightly at the gingival line and forming the surface of 
the root. Its function is to furnish the attachment of the fibers of the 
peridental membrane, which fastens the tooth to the bone. 

4. The pulp or soft tissue filling the central cavity in the dentin 
is the remains of the formative organ which has given rise to the dentin. 
Its functions are the formation of dentin and a sensory function. 

In describing the structure of the teeth and the arrangement of the 
structural elements of the tissues directions are described with reference 
to three planes : 

The mesio-disto-axial plane, a plane passing through the centre of the 
crown from mesial to distal and parallel with the long axis of the tooth. 

The bucco-linguo-axial plane, a plane passing through the centre of 
the crown from buccal to lingual and parallel with the long axis of the 
tooth. 

The horizontal plane, at right angles to the axial planes. 

The Supporting" Tissues. — The human teeth are supported on the 
maxillary bones, their alveolar processes growing up around the roots of 
the teeth, so that the roots fit into the holes in the bone. The calcified 
structures of the tooth and the bone are not, however, united, but the 
roots are surrounded by a fibrous membrane, the peridental membrane, 
or pericementum, which fastens the tooth to the bone. 

Enamel. 

The enamel differs from all other calcified tissues in the nature of 
the structural elements of which this tissue is made up, in the degree 
of calcification, and in origin, being the only calcified tissue derived 
from the epiblast. 

The enamel is formed from an epithelial organ derived from the 
epithelium of the mouth cavity and indirectly from the epiblastic germ 
layer, while all other calcified tissues are products of the mesoblast. 
In the case of bone and dentin the formative tissue is persistent. It 




97 



Ground section of a canine : E, enamel ; Cm, cementum ; D, dentin ; Pc, pulp chamber ; De, dento- 
enamel junction ; Ed, enamel defect ; G, junction of enamel and cementum at the gingival line ; 
Gt, granular layer of Tomes. (Reduced from photomicrograph made in three sections.) 



98 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

is possible in the bone at least, therefore, to have degenerative and re- 
generative changes, or the removal of part of the calcium salts and their 
replacement through the agency of the formative tissue ; while in the 
enamel no such regenerative change is possible, as the formative tissue 
disappeared when the tissue was completed and before the eruption of 
the tooth. 

The enamel is the hardest of human tissues. Chemically it is com- 
posed of the phosphates and carbonates of calcium and magnesium and 
a very small amount of the fluorids, water, also a very small amount 
of organic matter if any. 1 The enamel in the natural condition, bathed 
in the fluids of the mouth, contains a considerable amount of water. 
If dried at a little above the boiling-point of Avater, it gives up part 
of it and shrinks considerably, so as to crack in fine checks. If heated 
almost to redness, it suddenly gives off from 3 to 5 per cent, (of the 
dry weight) of water with almost explosive violence. These facts were 
demonstrated some years ago by Charles Tomes, 2 and account for most 
of what was formerly recorded as organic matter in old analyses. 

If we observe under the microscope the action of acids upon thin 
sections of enamel, when the inorganic salts are entirely removed, the 
structure of the tissue vanishes, there being no trace of organic matrix 
left as in the case of bone or dentin. In the growth of bone and 
dentin the formative tissue produces first an organic matrix (see Chap. 
II., p. 74) in the form of the tissue, and into this the inorganic salts are 
deposited, combining with the organic substances of the matrix. This 
union is comparatively weak, however, for by the action of acids the 
combination is broken up and the inorganic salts are dissolved ; or by 
heat the organic matter is removed, and in either case the form of the 
tissue will be maintained. 

In the case of the enamel, the formative organ produces organic 
substances containing inorganic salts, and the substances are arranged 
in the form of the tissue after the manner of a matrix ; but finally 
under the action of the formative organ all of the organic matter is 
removed and substituted by inorganic salts, whatever organic matter is 



1 Von Bibra gives the following analysis of enamel : 

Calcium phosphate and fluorid 89.82 

Calcium carbonate 4.37 

Magnesium phosphate 1-34 

Other salts 88 

Cartilage '. 3.39 

Fat 20 

Total organic 3.59 

" inorganic 96.41 

? Journal of Physiology, 1896. 



ENAMEL. 



99 



found in the fully formed tissue being the result of imperfect execution 
of the plan. 

The enamel is composed of two structural elements, the enamel rods, 
or prisms, sometimes called enamel fibers, and the interprismatic or 
cementing substance, both of which are calcified. It is to the arrange- 
ment of these structural elements that the characteristics of the tissue 
with which we are most concerned in operative procedures are due. 

While both the prisms and interprismatic substance of the enamel 
are calcified, or, better, composed of inorganic salts, the two substances 
— that is, the substance of the rods and the substance between the rods 
— show markedly different properties both chemical and physical. If 
treated with acid, the interprismatic substance is acted upon more 
rapidly than the rods, so that the latter become more conspicuous. By 
this means sections of the enamel may be etched to render it easier to 
study the direction and arrangement of the rods. If the action of the 
acid is carried far enough, the rods will fall apart before they are thern- 




Enamel rods isolated by caries. (About 465 X.) 

selves entirely dissolved. Fig. 79 is from the debris in a carious cavity, 
and shows rods isolated by the action of the acids of caries. 

The interprismatic substance is not as strong as the rods, so that in 
splitting or breaking the enamel the tissue separates on the lines of the 
cementing substance, occasionally breaking across a few rods but fol- 
lowing their general direction, the lines running between rods, not at 
their centres. 

In cleaving the enamel the chisel does not enter the tissue sepa- 
rating rod from rod, but the edge engages with the surface, and the 



100 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

force applied at an acute angle with the direction of the rods fractures 
the tissue in the lines of least resistance. If the edge be keenly 
sharp, it will enter the tissue slightly, and then the bevel acts as a 
wedge in addition to the force applied to the shaft of the instrument ;, 
but if the edge be dull, it will rest across the ends of many rods, will 
not engage with the surface, and the force applied will break and 
crumble the tissue but will not cleave it. 

The enamel rods, or prisms, are long, slender prismatic rods or 
fibers, five- or six-sided, pointed at both ends and alternately expanded 
and constricted throughout their length. They are from 3.4 to 4.5 
microns 1 in diameter, some of them apparently reaching the entire 
distance from the surface of the dentin to the surface of the enamel ; 
but as the diameter of the rods is the same at their outer and inner 
ends, and as the crown surface is much greater than the surface of den- 
tin covered by enamel, there are many rods which do not extend 
through the entire thickness. These short rods end in tapering points 
between the converging rods which extend the entire distance. To 
express this in terms of development : as the formation of enamel 
begins at the surface of the dentin, the increasing area of crown sur- 
face requires more ameloblasts, and as new ameloblasts take their place 
in the layer the formation of new enamel rods begins between the rods 
which were previously forming. These short rods are most numerous 
over the marginal ridges and at the points of the cusps, and will be 
considered more fully in connection with those positions. 

In ground sections cut at right angles to the direction of the rods 2 
the tissue has the appearance of a mosaic floor, the outline of the rods 
being more distinct if they have been marked out by treating the section 
slightly with acid (Fig. 80). In longitudinal sections (Fig, 81) the sides 
of the rods are not smooth and even like the sides of a lead pencil, but 
are alternately expanded and constricted. They are well illustrated by 
taking balls of soft clay and sticking them together one above another 
to form a rod, then putting a number of rods together so that by 
mutual pressure they take hexagonal forms. This illustrates also the 
manner of growth of the tissue in formation. The expansions and 
constrictions can be seen in rods that have been scraped from a cleaved 
surface of enamel, but better by isolating rods by the slight action of 
dilute acid (Fig. 82). 

In the construction of the tissue the rods are so arranged that the ex- 

1 A micron is the unit of microscopic measurement, and is equal to one one-thousandth 
of a millimeter. 

2 In describing the direction of enamel rods they are always considered as extending 
from the dentin to the surface, and the angle is formed at the surface of the dentin with 
the locating plane, either horizontal or axial. 



ENAMEL. 



101 



pansions of one rod come opposite to the expansions in the adjoining 
rods, and do not interlock with their constrictions. This arrangement 



Fig, 80. 




Transverse section of enamel rods. (About 80 X-) 

leaves alternately a greater and a less amount of cementing substance 
between them. 

Fig. 81. 





\ 










\ 














^> Vt ^ ,^ 






"" 


\\ \ \ 

















Enamel rods in thin etched sectic 



When observed under the microscope, the enamel rods show a char- 
acteristic appearance of light and dark lines running across them. 
These markings are similar to the striations of voluntary muscle fibers, 



102 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



and are described as the striation of the enamel. It is seen not only in 
isolated rods (Fig. 79), but also in sections ground in their direction (Fig. 



Fig. 82. 







.>x3l <* 



Enamel rods isolated by scraping. (About 800 X .) 

83). This appearance of striation in the enamel is caused by the alter- 
nate expansions and constrictions of the rods refracting the light like a 

Fig. 83. 




Enamel showing striation. (About 1000 X.) 



lens. In sections the expansions in adjoining rods are opposite to each 
other, the diiference in the refracting power of the prismatic and inter- 
prismatic substances producing the same effect. 



ENAMEL. 103 

The appearance of striation is the record in the fully formed tissue 
of the manner of growth, each dark stripe, or expansion, in a rod 
representing a globule of partially calcified material. The ameloblasts 
build up the rods by the addition of globule after globule, surrounding 
them with a cementing substance and completing the calcification of 
both. In this sense the striation of the enamel may be said to record 
the growth of the individual rods. 

While the enamel is a very hard substance when its structure is 
complete and perfect, its most striking physical characteristic is a ten- 
dency to split or crack in the direction of its structural elements when 
a break has been made in the tissue. While it is difficult to cut across 
the rods or make an opening on a perfect surface, if a break has been 

Fig. 84. 




Enamel showing direction of cleavage. (About 70 X.) 

established it is comparatively easy to split off the tissue from the sides 
of the opening when the rods lie parallel with each other. Fig. 84 
shows a field of enamel illustrating the w r ay in which the tissue splits 
or cleaves in the direction of the rods. 

Upon the axial surfaces the enamel rods are usually straight and 
parallel with each other, except where there has been some flaw or 
disturbance in development ; but upon the occlusal surface, although 
sometimes straight, they are very often much twisted and wound 
round each other, especially at their inner ends. This difference in the 
arrangement of the rods causes the greatest difference in the feeling 
of the tissue under cutting instruments. Such a specimen of enamel as 
shown in Fig. 85 can be cut away easily, the tissue breaking through 
to the dentin and splitting off in chunks ; while a specimen like Figs. 
86 and 87 will not cleave if supported upon sound dentin. If the outer 



104 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

Fig. 85. 




Straight enamel rods. (About 80 X.) 
Fig. 86. 



Gnarled enamel. (About 8( 



ENAMEL. 



105 



ends of the rods are straight, they will split part way to the dentin (Fig. 
87) ; but where they begin to twist round each other they will break 
across the rods. If the dentin is removed from under such enamel, it 
will break in an irregular way through the gnarled portion. 

From a study of the arrangement of the enamel rods in the forma- 
tion of the crown it is apparent that the plan is such as to give the 

Fig. 87. 




Gnarled enamel. (About 50 X.) 



greatest strength to the perfect structure, and may be likened to an arch. 
At the gingival border the rods are short and are inclined apically 6 to 10 
centigrades 1 (20° to 35°) from the horizontal plane. These short rods 



1 In the Centigrade division the circle 
is divided into one hundred parts, each 
called a centigrade. One centigrade is 
equal to 3.6 degrees of the astronomical 
circle, 25 centigrades to 90 degrees, 12J 
centigrades to 45 degrees. The cut gives 
a comparison of the two systems of meas- 
uring angles. 



270 




180" 

Centigrade division. 



106 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



are overlapped for a short distance by the cementum. This inclination 
grows less and less, and at some place in the gingival half of the middle 
third of the surface they are in the horizontal plane. At this point they 
are also usually perpendicular to the surface of the enamel. Passing 
from this point they become inclined more and more occlusally from the 
horizontal plane, at the junction of the occlusal and middle thirds about 8 
to 12 centigrades (28° to 40°) in bicuspids and molars, and 8 to 18 
centigrades (28° to 65°) in incisors and canines. In the occlusal third 
the inclination increases rapidly, and often the outer ends of the rods 

Fig. 88. 




Diagram of enamel rod directions, from a photograph of a bucco-lingual section of a superior 

bicuspid. 



are inclined more than the inner ends. Over the point of the cusps 
and the crest of the marginal ridges the rods reach the axial plane, 
though they are often very much twisted about each other in the inner 
half of their length. This position does not always correspond with the 
highest point of the cusp, but is inclined slightly axially from that posi- 
tion, and corresponds with the highest point of the dentin cusp. 

Passing down the central slope of the cusp, or ridge, the rods 
become again inclined away from the axial plane toward the groove, or 
pit, leaning toward each other where the two plates meet. The degree of 
inclination of the rods on the central slope of the cusps depends upon the 



ENAMEL. 



107 



height of the cusps ; the higher the cusp the greater the inclination from 
the axial plane. Fig. 88, a diagram from a photograph of a bucco- 
lingual section of a superior bicuspid, shows the plan of arrangement 
and illustrates the arch principle in the construction. 



Fig. 89. 




Stratification of enamel ; the cusp of a bicuspid: Be, dento-enamel junction; Ed, enamel defect 
showing in the heavy stratification band; Ig, interglobular spaces in the dentin. (About 
40X0 



In the study of longitudinal sections of the teeth, one of the most 
conspicuous structural features is the stratification bands, or brown 
bands of Retzius. These bands are not parallel with either the outer 
surface of the enamel or the dento-enamel junction. They begin at the 
tip of the dentin cusps and sweep around in larger and larger zones. 
These stratification bands are better seen in comparatively thick sec- 
tions, and are caused by the varying amount of pigment deposited with 



108 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



the calcium salts in the development of the tissue. They record the 
growth of enamel of the crown as a whole, as each line was at one time 
the surface of the enamel cap. These stratifications, or, better, incre- 
mental lines, are shown in Figs. 89-91. 

At the time the rod at A (Fig. 90) was completely formed the rod at 
B was just beginning to form at its dentinal end. From this it would 



Fig. 90. 




Incisor tip showing stratification or incremental lines. Rods at A were fully formed at the time 
the rods at B were beginning to form. (About 50 X.) 



seem that any structural defect due to imperfect development would not 
follow the direction of the enamel rods from the surface to the dentin, 
but would follow the stratification lines ; and if these structural defects 
influenced the penetration of caries, we should expect to have the direc- 
tion of penetration modified. Fig. 89 shows a structural defect in the 
enamel over a cusp following the stratification band, and it will be 
noticed also that there is a structural defect in the dentin at a corre- 
sponding position. 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS. 



109 



HISTOLOGICAL REQUIREMENTS FOR STRENGTH IN ENAMEL 

WALLS. 

1. The enamel must be supported upon sound dentin. 

2. The rods which form the cavo-surface angle must run uninter- 
ruptedly to the dentin and be supported by short rods, with their inner 
ends resting on the dentin and their outer ends abutting upon the cavity 
wall, where they will be covered in by the filling material. 

3. That the cavo-surface angle be cut in such a way as not to expose 
the ends of the rods to fracture in condensing the filling material against 
them. 

The first step, then, in the preparation of an enamel wall is to deter- 
mine the direction of the enamel rods by cleavage with a chisel or hatchet. 

Fig. 91. 




Enamel showing both striation and stratification 



In Figs. 92 and 93, No. 1 shows an enamel wall after cleaving the enamel 
with a hatchet. It will be noticed that the split has not followed the 
direction of the rods exactly, but has broken across them, slivering the 
rods as wood slivers in splitting. This would cause in the cut surface 
a whitish, opaque appearance. The plane of the enamel wall should be 
extended so as to form a small angle with the plane of the dentin wall, 
by shaving the surface with a very sharp hand instrument. No. 2 shows 
the same wall after it has been extended somewhat ; but it will be seen 
that it has not been extended enough, for the rods forming the sur- 
face at A do not reach the dentin, but run out at B on the cavity wall, 
and that piece would chip out in packing against it or if force came upon 
the surface afterward. The angle should be extended so as to produce- 



110 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY 




HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS. Ill 






b b 




Preparation of enamel wall in gnarled enamel: 1. Enamel wallas cleaved, showing breaking 
across rods and slivering at a. 2. Wall as smoothed but not extended to remove short rods 
whose inner ends are cut off at b. 3. Wall extended and trimmed to a position of strength. 
D, dentin ; De, dento-enamel junction ; c, cavo-surface angle ; b, point where inner ends of 
rods are cut off; a, slivering of the tissue. (About 80 X.) 



112 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



the plane shown in No. 3 ; then the cavo-surface angle may or may not 
be bevelled as the position demands. 

In some positions, as on the axial surfaces, it is not possible to ex- 
tend the plane of the entire enamel wall as described ; all that can be 
done is to shave the cut surface, leaving the wall in the direction of the 
enamel rods, and then the margin is strengthened by bevelling the cavo- 

Fig. 94. 




Occlusal fissure in a superior bicuspid, showing direction of rods. (About 80 X.) 



surface angle, so that the rods forming the margin are supported by at 
least a few rods which are covered by filling material. 

In cutting: out the fissures on the occlusal surfaces of molars and 
bicuspids, the rods are inclined centrally from the axial plane, as seen 
in Fig. 94. In opening a fissure the lines of cleavage will not be in 
the axial plane, but sloping inward toward the body of the cusp, in the 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS. 113 



direction indicated by the direction of the cracks in Fig. 94. The outer 
ends of the enamel rods must be shaved away, to bring the plane of 
the enamel wall parallel with the dentin wall or into the axial plane. 
When this has been done a strong margin has been formed, for the 

Fig. 95. 





«•" 








?s: 


r 








>, v. 


\ 




•■ ' 


■\i 










\ ' J ' 






/ 


X 




"♦<." y \ 


.-,. t 





Preparation of enamel Avails in occlusal fissure cavities (the same as Fig. 94). 

rods which form the point of the cavo-surface angle are supported by 
the piece A, B, C (Fig. 95), made up of rods resting upon sound dentin 
and covered by the filling material. Often the angle will be too sharp, 
however, and the cavo-surface angle should usually be bevelled to pro- 
tect the margin from accident. This illustration may be taken as typ- 
ical of occlusal cavities. 

8 



114 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



Fig. 96. 




Preparation of enamel walls in a buccal cavity in a molar : G, gingival wall ; 0, occlusal wall. 

(About 70 X.) 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS. 



115 



Fig. 96 shows a cavity prepared in the buccal surface of an upper 
molar. The occlusal margin is placed in the occlusal half of the middle 
third, and the gingival margin in the gingival half of the gingival third 



Fig. 97. 




2. Wall as trimmed. 
Preparation of occlusal wall of Fig. 96. (About 70 X.) 

of the surface. In the occlusal wall the rods are inclined occlusally 
about 8 centigrades (28°) from the horizontal plane. After cleaving, 
the broken and slivered rods should be shaved away, but the angle can- 



116 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



not be increased without making the margin of filling material too thin ; 
the rods forming the margin should therefore be protected by bevel- 
ling the cavo-surface angle. At the gingival wall the rods are inclined 
apically from the horizontal plane about 6 centigrades (20°). The 
wall should be shaved in that plane, increasing the angle a little, and 
the cavo-surface angle should be bevelled. Fig. 97 shows the occlusal 
enamel wall alone, after cleaving and trimming into form. Such 
enamel walls may be taken as typical of axial surface cavities, the 

Fig. 98. 




Structure of enamel about a fissure : B, buccal side ; L, lingual side. (About 70 X.) 

angle of the enamel with the dentin wall being determined by the 
direction of the enamel rods in the position where the margin is laid. 

Grooves, fissures, and pits are always positions of weakness, and 
when a cavity approaches a groove or pit a good margin, histologically, 
cannot be prepared without cutting beyond it. Fig. 98 shows an 
occlusal fissure in a bicuspid, which illustrates the conditions of struct- 
ure characteristic of these positions. The rods are inclined toward 
the fissure, and between the bottom of the fissure and the dentin are 
very irregular. If a cavity wall were made to approach this fissure from 
the lingual side, so as to come to the dotted line, the wall would have 
to be inclined 6 to 8 centigrades (20° to 28°) from the axial plane toward 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS. 117 

the fissure, and then the cavo-surface angle bevelled, when the condi- 
tions would be similar to those in the wall of an axial surface cavity, 
and not as strong as the location requires. Not only is this true, but 
it also leaves a vulnerable point next to the margin of the filling — a 
point of liability. Cutting just beyond the fissure, the wall may be 
left in the axial plane and have an ideally strong margin, and the 
point of liability is removed. To state the conditions in general 

Fig. 99. 




TBucco-lingual section of upper bicuspid. Enamel is broken from grinding: A to B, area of weak- 
ness for enamel margins. (About 20 X.) 



terms, a strong margin is more easily obtained where enamel rods are 
inclined toward the cavity than where they are inclined away from the 
cavity. 

The points of cusps and the crests of marginal ridges are positions of 
strength in the perfect tissue ; but when a cavity margin approaches 
them they become points of weakness, because it is impossible to sup- 
port properly the rods Avhich form the margin. Over the marginal 



118 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



ridges are many short rods which do not reach the dentin, and these 
are usually very much twisted about each other, so as to form the 
strongest possible keystone in the perfect structure. In preparing a 



Fig. 100. 




Enamel over tip of dentin cusp : D, dentin cusp. (About 80 X.) 



margin in such a position it is impossible to have the rods which 
form the margin reach the dentin with their inner ends, and these 
short rods are sure either to break in completing the operation or to 



HISTOLOGICAL REQUIREMENTS IN ENAMEL WALLS. 



119 



break out later. The arrangement of enamel rods in such positions is 
to be borne in mind, especially when extending approximal cavities in 
incisors toward the lingual side and in large pit cavities in incisors. A 
similar condition is found over the points of the cusps. Fig. 99 shows 
a bucco-lingual section of an upper bicuspid. It will be noticed that 
the rods forming the point of the cusp are not in the axial plane, and 









Fig. 


101. 










to J 


















9. 














| 




f-J'f' 


/■ 










.j y '' 


' 4 




H 


*' 


















s" 




















\WM 






£t. ■■. 






/ 

7 


Wl 






.'3 




HBb7* 


% 


3^ 





Tip of an incisor. (About CO X.) 



do not reach the tip of the dentin cusp, but reach the dentin a little 
way down on the outer slope. The enamel covering the tip of the 
dentin contains many short rods, and they are very much twisted about 
each other, so that the area from A and B to the point of the cusp is an 
area of weakness for the cavity margins. If the margin reaches this 
area, the cusp must be cut away and the enamel Avail carried out in the 
horizontal plane. Fig. 100 shows this area more highly magnified, and 



120 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



illustrates the structure. It will be noticed that, in grinding, some of 
the short twisted rods have broken out of the section. 

Fig. 101 shows the tip of an incisor in labio-lingual section, and is of 
interest in relation to the formation of margins in step cavities in in- 
cisors. The tip of this tooth has been Avorn off in use. The illustration 
shows that the great inclination of the rods toward the axial plane in 
the occlusal third of the incisors is such as to bring the wear almost at 
right angles to the direction of the rods. 

Dentin. 

The structure of dentin is of comparatively little interest in the 
present consideration, as its histological forms do not directly influence 

Fig. 102. 





L 



-:: 






Dentin at dento-enamel junction, showing tubules cut longitudinally : Dt, dentinal tubules ; D, 

dentin matrix. (About 760 X .) 



the cutting of the tissue in the excavation of cavities. Its histological 
forms have, however, much to do with the penetration of caries and 
with other considerations which are of importance to the intelligent 
practice of operative dentistry. 



DENTIN. 



121 



Dentin belongs to the connective-tissue group, and is made up of 
a solid organic matrix impregnated with about 72 per cent, of inorganic 
salts 1 and pierced by minute canals or tubules, which radiate from a 
central cavity which contains the remains of the formative organ, or 
pulp. The minute canals, or dentinal tubules, are occupied in life 
by protoplasmic processes from the odontoblastic cells which form the 
outer layer of the pulp. Dentin contains two kinds of organic matter, 
the contents of the tubules and the organic basis of the matrix. The 
dentin matrix, after the removal of the calcium salts by acids, yields 
gelatin on boiling and resembles the matrix of bone, reacting in a similar, 
though not identical, way with staining agents. The portion of the 
matrix immediately surrounding the tubules shows different chemical 

Fig. 103. 




Dentin showing tubules in cross-section : Dt, dentinal tubules ; D, dentin matrix ; S, shadow of 
sheaths of Neumann. (About 1150 X.) 

characteristics from the rest of the matrix, resembling elastin, and re- 
sisting the action of strong acids and alkalies after the rest of the 
tissue has been destroyed. This portion of the matrix surrounding the 
tubules and lying next to the fibrils is known as the sheaths of Neumann. 
The dentinal tubules are from 1.1 to 2.5 microns in diameter, and 
are separated from each other by a thickness of about 10 microns of 
1 Von Bibra gives the following analysis of dentin : 

Organic matter 27.61 

Fat 40 

Calcium phosphate and fiuorid 66.72 

Calcium carbonate 3.36 

Magnesium phosphate 1.08 

Other salts 83 



122 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



dentin matrix. This is fairly uniform throughout the dentin. The 
character of the tubules is different in the crown and root portions. 
In the crown the tubules branch but little through most of their 
course ; but in the outer part, close to the enamel, they branch and 
anastomose with each other quite freely. Fig. 102 shows a field of 
dentin just beneath the enamel, as seen with a high power, and shows 
the diameter of the tubules, their branching, and the amount of matrix 
between one tubule and the next. The relation of one tubule to each 
other is shown also in sections cut at right angles to their direction 
(Fig. 103). In the crown portion the tubules pass from the pulp chamber 





Fig. 104. 




A — -x 

B 




\ 

V 

1 




~^**2j 


p^j • 



Crown of a molar, mesio-distal section, showing penetration of caries : A, caries penetrating den- 
tin ; B, line of abrasion ; P, pulp chamber. (About 20 x.) 



to the dento-enamel junction in sweeping curves, so as to enter the pulp 
chamber at right angles to the surface, and end next to the enamel at 

right angles to that surface. This produces S- or F-shaped 

curves, which are known as the primary curves of the tubules. Through- 
out their course the tubules are not straight, but show a great many 
wavy curves, known as the secondary curves. These appear as waves 
when seen in longitudinal sections, but are really the effect of an open 
spiral direction, as is seen by changing the focus of the microscope in 
studying sections cut at right angles to the direction of the tubules. 



DENTIN. 

Fig. 105. 



123 




Dentin from the root, showing tubules cut longitudinally. (About 700 X.) 



Fig. 106 




Dento-enamel junction. (About 70 X 



124 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



The branches throughout their length are few and small, and are given 
off at an acute angle to the direction of the tubule ; but just before the 
enamel is reached the tubules fork and branch, producing an appearance 
similar to the delta of a river. These branches are given off from the 
tubules for some little distance back from the enamel, and they anasto- 
mose with other tubules very freely. The branching of the tubules in 
their outer portion causes the spreading of caries just beneath the 
enamel, the micro-organisms growing through the branches from tube 

Fig. 107. 




Interglobular spaces in dentin : Ig, first line of interglobular spaces ; Ig', second line of inter- 
globular spaces. (About 30 X.) 



to tube, and so spreading sideways beneath the enamel plates, and then 
penetrating the dentin in the direction of the tubules. Fig. 104 shows 
the penetration of caries in the dentin. It will be noticed that in decay 
starting at the contact point there has been more spreading under the 
enamel than in that starting at the gingival line, but in both positions 
the penetration has followed the direction of the tubules. 

In the root portion the tubules pass out from the pulp canals at right 
angles to the long axis of the tooth and pass directly out to the cemen- 
tum, showing only the secondary curves. Throughout their course they 



DENTIN. 



125 



give off a great many fine branches passing through the matrix in all 
directions from tubule to tubule. These branches are so numerous that 
in sections which have been mounted in such a way as to leave air in 
them, or if the tubules have been filled with coloring-matter, they give 
the impression of looking through a hazel bush ; or they may be likened 
to the fine rootlets of a plant. These fine branches are shown in 
Fig. 105, and the character of the dentin in the root portion is to be 
compared with that in the crown portion as shown in Fig. 102. The 

Fig. 108. 




Granular layer of Tomes : L, lacunae of cementum ; Gt, granular layer of Tomes; Ig, interglobular 

spaces. (About 200 X.) 

outermost layer of the dentin next to the cementum contains many 
small irregular spaces, which connect with the dentinal tubules and give 
to the tissue when seen with low powers a granular appearance. This 
layer was first described by John Tomes as the granular layer, and has 
since been usually called the granular layer of Tomes. The spaces of 
the granular layer are probably filled by the enlarged ends of the den- 
tinal fibrils. The same appearance is sometimes seen beneath the enamel, 
but is never as well marked as next to the cementum. 

The dentin at the dento-enamel junction seldom presents a smooth 
surface, but the inner surface of the enamel plate shows rounded pro- 



126 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



jections, between which the dentin extends. In sections this gives to 
the dento-enamel junction a scalloped appearance, as shown in Fig. 106; 
and often the deceptive appearance of the dentinal tubules penetrating 
for a short distance between the enamel rods. 

In many specimens made by grinding dried teeth large irregular 
spaces are very conspicuous in the dentin. They usually occur in lines 
or zones at about uniform depth from the surface. These have been 
called the interglobular spaces. They are really not spaces at all, but 
are areas of imperfect development in which the dentin matrix has not 

Fig. 109. 




Secondary dentin : A, margin of primary dentin, showing a few of the tubules continuing into the 
secondary dentin ; P, pulp chamber. (About 80 X.) 

been calcified. The dentinal tubules pass through them without inter- 
ruption. In a dried specimen the organic matrix shrinks, and the 
resulting space becomes filled with the debris of grinding, so as to give 
the appearance of black spaces. Fig. 107 shows two quite distinct layers 
of interglobular spaces, the second much more marked than the first ; 
and in the enamel at a position corresponding to the first is seen an im- 
perfection of structure marked by the very dark stratification band. 
This is shown best in the region of the cusp (Fig. 89) from the same 
section. Interglobular spaces in the root portion of the dentin are 
shown in Fig. 108, close to the granular layer of Tomes. 



PULP. 127 

The formation of dentin is not complete at the time of eruption of 
the tooth, but continues for an indefinite period, thickening the layer of 
dentin at the expense of the pulp. When the typical amount of den- 
tin has been formed the growth ceases, and does not begin again unless 
excited by some irritation to the pulp or the pulp of some other tooth 
of the same side, which leads to the formation of secondary dentin. 
Secondary dentin is never as perfect in structure as primary dentin ; 
the tubules are smaller, fewer, and much more irregular. Often in 
ground sections several periods of formation can be determined by dif- 
ferences of structure, each deposit becoming successively more and more 
imperfect in structure. This is shown in Fig. 109. 

Pulp. 

The dental pulp is the soft tissue occupying the central cavity of the 
dentin. It is made up of embryonal connective tissue and contains a 
large number of bloodvessels and nerves. Like all connective tissues, 
the intercellular substance is large in amount and the cells are widely 
scattered in this soft, jelly-like tissue, which contains but few fibers. 
We recognize four kinds of cells in the pulp : the odontoblasts, form- 
ing the outer surface of the pulp next to the dentin; and round, spindle- 
shaped, and stellate connective-tissue cells. 

ARRANGEMENT OF CELLS. 

The odontoblasts are tall columnar cells, sometimes club-shaped, and 
in older tissues, which have ceased to be functional, sometimes becoming 
almost spherical. They form a continuous layer over the entire surface 
of the pulp, being everywhere in contact with the dentin. The layer 
has been called the membrana eboris, or the " membrane of the ivory/' 

The nuclei of the odontoblasts are large and oval, containing a large 
amount of chromatin, and are very different from the nuclei of ordinary 
connective-tissue cells. 

Three kinds of processes have been described in connection with the 
odontoblasts : 

1. The dentinal fibril processes, or fibers of Tomes. These are long, 
slender protoplasmic processes projecting from the dentin end of the 
cell into a dentinal tubule, and running through the tubule to the outer 
surface of the dentin. Usually there is but one fibril extending from 
each odontoblast, but sometimes two can be seen, extending into two 
tubules. These fibrils can be demonstrated in decalcified sections or 
by removing the pulp from a recently extracted tooth by cracking the 
tooth, and carefully lifting the pulp out of the pulp chamber, and then 
either teasing or sectioning. Fig. 110 shows the fibrils projecting from 



128 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

the surface ; but in this section the cut was not in the direction of the 
long axis of the odontoblasts, but obliquely through them. Fig. Ill 
(from a photograph by Rose) shows the form of the odontoblasts in a 



Fig. 110. 




Odontoblasts. The section cuts obliquely through the odontoblasts : F, fibrils ; N, nuclei 
of odontoblasts ; N', nuclei of connective-tissue cells ; W, layer of Weil, not well shown. 
(About 80 X.) 

young tooth in which formation of dentin is actively progressing, with 
the fibrils in the dentinal tubules. 

2. Lateral processes projecting from the sides of the cells and unit- 
ing one with another in the formation of the layer. 

3. Pulpal processes, projecting from the pulpal ends of the odonto- 
blasts into the layer of Weil. 

The odontoblasts, as the name indicates, are the dentin-forming 
cells. They superintend the formation and calcification of the dentin 
matrix, the fibril being left behind surrounded by the formed tissue. 
Whether the fibrils have any share in the formation and calcification of 
the dentin matrix has been a matter of controversy. 

The relation of the fibrils to the transmission of sensation is also a 
matter of dispute ; but at present the weight of evidence is that they 
in some way transmit impressions to the sensory nerves of the pulp. 

Just beneath the layer of odontoblasts is a zone which contains very 
few connective-tissue cells, In thin sections, especially in the body of 
the pulp, this appears as a clear layer about half as thick as the layer 
of odontoblasts. It is known as the layer of Weil. Just beneath the 



PULP. 



129 



layer of Weil the connective-tissue cells are especially numerous and 
form a more or less distinct layer of closely placed cells. In the rest 
of the body of the pulp the cells are about uniformly distributed through- 
out the intercellular substance. These connective-tissue cells are of the 
characteristic forms, rather small, containing a small but deep-staining 
nucleus, the protoplasm stretching out into slender projections in two 
directions to form the spindle cells, or in more than two directions to 
form the stellate cells. The stellate forms are more common in the 
body of the pulp, the spindle form in the canal portions. The round 

Fig. 111. 




Odontoblasts and forming dentin: E, forming enamel; D, forming dentin; 0, odontoblasts; 
Dp, body of dental papilla. (From photomicrograph by Rose.) 

cells are comparatively few in number, and are probably young cells 
which have not yet acquired the adult form. 



BLOODVESSELS OF THE PULP. 

The blood-supply of the pulp is extremely rich, several arterial ves- 
sels entering in the region of the apex of the root, often through several 
foramina. These large vessels extend occlusally through the central portion 
of the tissue, giving off many branches which break up into a very close 
and fine capillary plexus (Fig. 112). From the capillaries the blood is 
collected into the veins, which pass apically through the central portion 
of the tissue. A very striking peculiarity of the bloodvessels of the pulp 
is the thinness of their walls. Even the large arteries show scarcely any 

9 



130 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

Fig. 112. 




Diagram of the bloodvessels of the pulp. (Stowell.) 

condensation of fibrous tissue around them to form the usual adven- 
titious layer, and usually contain but a single involuntary muscle fiber 

Fig. 113. 













A pulp bloodvessel, showing the thin wall : C, blood corpuscles in the vessel ; Bl, bloodvessel wall 
showing nuclei of endothelial cells ; N, nuclei of connective-tissue cells in the body of the 
pulp ; I, intercellular substance, showing a few fibers. (About 200 X.) 

representing the media, while the walls of even the large veins are made 
up of only the single layer of endothelial cells forming the intima, and 



PULP. 131 

are in structure like large capillaries (Fig. 113). This peculiarity of the 
bloodvessel walls is of great importance, as it renders the tissue specially 
liable to such pathologic conditions as hyperemia and inflammation. 

NERVE OF THE PULP. 

Several comparatively large bundles of medullated nerve fibers, con- 
taining from six or eight to fifteen or twenty fibers, enter the pulp 
in company with the bloodvessels and pass occlusally through the 
central portion of the tissue. These bundles branch and anastomose 
with each other very freely. Most of the fibers lose their medullary 
sheath before reaching the layer of Weil, in which position they form a 
plexus of non-medullated fibers ; from these fibers free endings are given 
off, which penetrate between the odontoblasts. In some cases these 
have been followed over on to the dentinal ends of the odontoblasts, 
but in no instance have they been followed into the dentinal tubules. 

THE FUNCTIONS OF THE PULP. 

The pulp performs two functions, a vital and a sensory. 

The vital function is the formation of dentin, and is performed 
by the layer of odontoblasts. This is the principal function of the 
pulp, and it is first manifested in the development of the tooth before 
the dentinal papilla is converted into the dental pulp by being inclosed 
in the formed dentin. After the tooth is fully formed the vital func- 
tion is not manifested unless the pulp is stimulated by some excitation 
affecting trophic centres and which causes the formation of secondary 
dentin. There are some exceptions where the formation is entirely 
local. 

The Sensory Function. — In regard to sensation, the pulp resembles 
an internal organ. It has no sense of touch or localization, and re- 
sponds to stimuli only by sensations of pain. The pain is usually 
localized correctly with reference to the median line, but, aside from 
that, is localized only as it is referred to some known lesion. If several 
pulps on the same side of the mouth and in teeth of both the upper 
and lower arches were exposed so that they could be irritated without 
impressions reaching the peridental membrane, and the patient were 
blindfolded, it would be impossible for him to tell which of the pulps 
was touched. The pain originating from a tooth pulp may be referred 
to the wrong tooth or to almost any point on the same side supplied by 
the fifth cranial nerve. 

The pulp is especially sensitive to changes of temperature, but is 
incapable of differentiating between heat and cold ; this fact is often 
made use of in differential diagnoses (see Chapter XYL). The pulp is 



132 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



also very sensitive to traumatic and chemical irritations, even when 
these are conveyed to it through the agency of the dentinal fibrils. Dr. 
Huber has suggested l that this transmission may be accomplished by 
the traumatic or chemical action upon the fibrils setting up metabolic 
changes in the odontoblastic cells, which act as stimuli to the sensory 
nerves ending between the cells of that layer. 



Cementum. 

The cementum covers the surface of the dentin apically from the 
border of the enamel, lapping slightly over the enamel at the gingival 
margin (Fig. 114). It forms a layer, thickest in the apical region and 







Fig. 11 


i. 






l~--'~ ... -' 




E 




\ "- i 


-• \v-<-'~ : S\ 




':'■■:■■'■•'■ ■ . 




■^■■■:- : Jl 


Q 




m . ' 






1 . ' ■ ■ j__ 


f 


4 V >-- 



Gingival border of enamel, showing the cementum overlapping 

dentin. (About 40 X.) 



D. 



it: E, enamel; C, cementum ; D, 



between the roots of bicuspids and molars, and becoming thinner as the 
gingival line is approached. The cementum resembles subperiosteal 
bone in structure, but differs from it in the character and arrangement 
of the lacunae and in the absence of Haversian systems ; the layers, or 
lamellse, of the cementum also are less uniform in character than those 
of bone. 

The function of the cementum is to furnish attachment for the 
fibers of the peridental membrane which holds the tooth in its position. 
The surrounding tissues are never in physiologic connection with the 
outer surface of the dentin, except to form cementum over it or to 
remove its substance by absorption ; and when absorption of the dentin 
1 Dental Cosmos, October, 1898. 



CEMENTUM. 



133 



has occurred on the surface of a root it is never repaired except by the 
formation of cementum to fill up the cavity and reattach the membrane. 
The cementum is intermittently formed during the functioning of 
the tooth, being added layer after layer over the entire surface of the 
root, the difference in thickness of the tissue in the gingival and apical 
portions being chiefly, though not entirely, due to the difference in 
thickness of each layer in the two positions (Figs. 114, 115). The 
cementum on the roots of newly erupted teeth is thin, and on the roots 
of teeth of old persons is thick. This continued formation of cementum 

Fig. 115. 




Cementum near the apex of the root : Gt, granular layer of Tomes ; L, lacunae , b, point at which 
fibers Avere cut off and reattached. (About 54 X.) 



is due to the necessity for change and reattachment of the fibers of the 
membrane. 

In the gingival portions, where the cementum is thin, the tissue is 
clear and apparently structureless, and usually contains no lacunae ; 
while in the apical half and between the roots the lacunae are numerous. 
In general, wherever the lamellae are thin, the lacunae are absent; but 
where the lamellae are thick they are found. The canaliculi which 
radiate from the lacunae are not as regular as in the case of the lacunae 
of bone. Sometimes they are numerous, sometimes few ; they may 
extend from a lacuna in all directions, or they may be confined to one 
side, usually the side toward the surface of the cementum (Fig. 116). 



134 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

Fig. 116. 



H, 



D. 




Thick lamellae of cementum with many lacunae, filling an absorption in dentin: L, lacunae; H, 
Howship's lacunae filled; D, dentin. (About 250 X.) 



Fig. 117. 




Two fields of cementum showing penetrating fibers : Gt, granular layer of Tomes ; C, cementum 
not showing fibers ; F, penetrating fibers. (About 54 X.) 



PERIDENTAL MEMBRANE. 135 

The cementum is penetrated through all its layers by fibers of the 
peridental membrane which have been imbedded in the matrix of the 
tissue and calcified along with it. The first layer, — that is, the one next 
to the dentin, — is usually structureless and shows no fibers in it, at 
least in its inner half. In ground sections the imbedded fibers often 
appear in a number of layers, while they are not apparent in the rest 
of the thickness. This is because just before and just after the forma- 
tion of the layers in which they appear the fibers were cut off and 
reattached, changing their direction, so that in the other layers the 
fibers are cut transversely or obliquely. This is illustrated in Fig. 117. 
These imbedded fibers are very numerous in some places. If properly 
stained, the tissue seems almost a solid mass of fibers. In ground sec- 
tions these have sometimes been mistaken for minute canals from the 
fact that they are not always as fully calcified as the cementum matrix, 
and shrinkage causes the appearance of little open canals. 

Hypertrophies of the cementum (formerly often called exostoses, or 
excementoses) are very common. The increased thickness may be of 
one lamella or of several lamella? in the region of the hypertrophy, or 
all of the layers from first to last may take part in it. Small local 
thickenings of a single lamella are seen in connection with the peri- 
dental membrane wherever a specially strong bundle of fibers is to be 
attached to the root to support the tooth against some special strain. 

Peridental Membrane. 

The peridental membrane may be defined as the tissue which fills 
the space between the root of the tooth and the bony wall of its 
alveolus, surrounds the root occlusally from the border of the alveolus, 
and supports the gingivus. It has been referred to under many names, 
as pericementum, dental periosteum, alveolo-dental periosteum, etc. 
While this tissue performs the functions of a periosteum for the bone 
of the alveolus, it diifers in structure from the periosteum in any 
position, so that any name including the word periosteum or implying 
a double membrane should be avoided. 

The peridental membrane belongs to the class of fibrous membranes, 
and is made up of the folloAving structural elements : 

1. Fibers. 2. Fibroblasts. 3. Cementoblasts. 4. Osteoblasts. 5. 
Osteoclasts. 6. Epithelial structures which have been called the glands 
of the peridental membrane. 7. Bloodvessels. 8. Nerves. 

The peridental membrane performs three functions : a physical 
function, maintaining the tooth in relation to the adjacent hard and 
soft tissues ; a vital function, the formation of bone on the alveolar 
wall and of cementum on the surface of the root ; and a sensory 



136 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



function, the sense of touch for the tooth being exclusively in this 
membrane. 

The fibrous tissue of the membrane is of the white variety, and 
may be divided into two classes, the principal fibers and the indifferent or 



Fig. 118. 




Diagram of the fibers of the peridental membrane : G, gingival portion ; Al, alveolar portion ; Ap, 
apical portion. (From a photograph of a section from incisor of sheep.) 



interfibrous tissue. The principal fibers may be defined as those which 
spring from the cementum and are attached at their other end to the 



PERIDENTAL MEMBRANE. 



137 



bone of the alveolar wall, to the outer layer of the periosteum covering 
the surface of the alveolar process, to the cementum of the approximating 



Fig. 119. 




Longitudinal section of peridental membrane from young sheep, showing fibers penetrating 
cementum: D, dentin; C, cementum, showing imbedded fibers; F, fibers running to outer 
layer of periosteum covering the alveolar process ; F', fibers running to the bone at the border 
of the process ; B, bone. (About 80 X.) 



tooth, or become blended with the fibrous mat of the gum supporting 
the epithelium. They were so called by Dr. Black, not only because 



138 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



they form the principal bulk of the tissue, but they also perform the 
principal function of the membrane, the support of the tooth and sur- 
rounding tissues. The interfibrous tissue, also of the white variety but 
made up of smaller and more delicate fibers, is found filling spaces 
between the principal fibers and surrounding and accompanying the 
bloodvessels and nerves. 

For convenience of description and study, the peridental membrane 
is divided into three portions : the gingival, that portion which surrounds 
the root occlusally from the border of the alveolar process ; the alveolar, 
the portion from the border of the process to the apex of the root ; and 



Fig. 120. 




D. 

N. 

F. 

a 

F l 
■F* 
B. 



Longitudinal section of the peridental membrane in the gingival portion- D, dentin; N, 
Nasmyth's membrane ; C, cementum ; F, fibers supporting the gingivus ; F 1 , fibers attached 
to the outer layer of the periosteum over the alveolar process ; F 2 , fibers attached to the bone 
at the rim of the alveolus ; B, bone. (About 30 X.) 

the apical portion, surrounding the apex of the root and filling the 
apical region (Fig. 118). 

The principal fibers spring from the cementum, the cementoblasts 
building up the matrix around them and then calcifying both matrix 
and fibers, in this way implanting their ends into the surface of 
the root. In Fig. 119 the fibers are seen passing through the last- 
formed layer of cementum. In most positions the fibers as they spring 
from the cementum appear as well-marked bundles of fine fibers. A 
short distance from the surface of the root they break up into smaller 
bundles, which interlace and are reunited into larger bundles, to be 



PERIDENTAL MEMBRANE. 



139 



attached at their other extremity to the bone, cementum, or fibrous 
tissue. 

To arrive at an understanding of the arrangement of the fibers of 
the peridental membrane, they must be studied in both longitudinal and 
transverse sections. In longitudinal sections of the membrane, in the 
gingival portion (Fig. 120), the fibers springing from the cementum at 
the gingival line pass out for a short distance at right angles to the 
long axis of the tooth and then bend sharply to the occlusal, 1 passing 



Fig. 121. 




Transverse section of the peridental membrane in the gingival portion (from sheep) : E, epi- 
thelium : F, fibrous tissue of gum ; B, point where peridental membrane fibers are lost in fibrous 
mat of the gum ; P, pulp ; F' , fibers extending from tooth to tooth. (About 30 X.) 

into the gingivus to support it and hold it closely against the neck of 
the tooth. These fibers are most numerous on the lingual side, where 
food is brought against the gingivus with force in mastication and tends 
to crush it down. In the middle of the gingival portion the fibers pass 
out at right angles to the axis and are blended with the fibrous mat of 
the gum on the labial and lingual sides, or are attached to the cementum 
of the adjoining teeth on the approximal sides. A little farther from the 

1 In describing the direction and inclination of peridental membrane fibers they are 
always traced from the cementum to the bone, the angle with the horizontal plane being 
formed at the surface of the cementum. 



140 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



gingival line the fibers are inclined slightly apically, passing over the 
border of the process to be attached to the outer layer of the periosteum. 
These fibers are specially large and strong. Just at the rim of the 
alveolus the fibers are inclined slightly apically and are inserted into 
the bone, forming the edge of the process. 

In transverse sections of the membrane in the gingival portion (Fig. 
121) the fibers spring from the cementum in large bundles ; at the centre 
of the labial surface they extend directly outward, breaking up into 
smaller bundles, passing around bloodvessels and bundles of fibers, and 
blending with the fibrous tissue supporting the epithelium. Passing 
mesially and distally toward the corners of the root, the fibers swing 
around laterally and pass to the cementum of the next tooth. On the 

Fig. 122. 




Fibers at the border of the alveolar process (from sheep): D, dentin ; C, cementum; F, fibers ex- 
tending from cementum to bone ; Bl, bloodvessel; B, bone. (About 80 X.) 



approximal sides the fibers suddenly divide into smaller bundles, which 
wind in and out around bloodvessels, and bundles of fibers which pass 
into the gingivus and are reunited into large bundles to be inserted into 
the cementum of the next tooth. On the lingual side the arrangement 
is like that of the labial, except that the distance to which the fibers of 
the membrane can be followed before they are lost in the fibrous mat of 
the gum is usually greater than on the labial. 

In the occlusal third of the alveolar portion of the membrane the 
fibers pass, at right angles to the axis of the tooth, directly from the 
cementum to the bone. In this position the fibers are large and do not 
break up into smaller bundles, but the original fibers can be followed 



PERIDENTAL MEMBRANE. 



141 



Fig. 123. 




Transverse section of the peridental membrane in the occlusal third of the alveolar portion 
(from sheep) : M, muscle fibers; Per, periosteum ; .4/, bone of the alveolar process; Pd, peri- 
dental membrane fibers ; P, pulp ; D, dentin ; Cm, cementum. 



142 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

uninterruptedly from the cementum to the bone (Figs. 119 and 122). 
In the middle third the fibers are inclined occlusally, and this inclina- 
tion increases as the apical third is approached. In the apical third 
the inclination is greatest, and the fibers as they arise from the cemen- 
tum are very large and break up into fan-shaped fasciculi as they pass 
across to the bone. In the apical portion the fibers radiate from the 
apex in all directions across the apical region and spread out in fan- 
shaped bundles like those in the apical third of the alveolar portion. 

In a transverse section near the border of the alveolus (Fig. 123), at 
the centre of the labial surface of the root, the fibers are seen to extend 
directly out from the surface of the root to the bone of the process, ex- 
cepting where they are diverted to pass around bloodvessels. Passing 
around distally at the corner of the root, the fibers swing laterally so as 
to be almost at a tangent to the surface of the root, and are inserted 
much farther to the distal on the wall of the alveolus. A similar ar- 
rangement is noticed at the other corners of the root, though these 
tangential fibers are usually more marked at the distal than at the 
mesial corners. 

Studying the arrangement of the fibers Avith reference to the physical 
function of the membrane, it is seen to be the best that could be 
devised to support the teeth against the force of mastication and to 
support the tissues about them. In the gingival portion the fibers 
passing from tooth to tooth form the foundation for the gingiva? between 
the teeth filling the interproximal spaces ; so that if these fibers are 
cut off from the cementum, by extending a crown band too far, or by 
the encroachment of calculary deposits beginning in the gingival space, 
the gingivus drops down and no longer fills the interproximal space. In 
the alveolar portion the fibers at the border of the process and those 
at the apex of the root together support the tooth against lateral 
strain, while those in the rest of the alveolar portion are so arranged 
as to swing the tooth in its socket and support it against the force 
of occlusion (Fig. 118). As seen from the transverse section, the fibers 
of the occlusal third of the alveolar portion are so arranged as to sup- 
port the tooth against forces tending to rotate it in its socket. 

CELLULAR ELEMENTS OF THE MEMBRANE. 

The fibroblasts are spindle-shaped or stellate connective-tissue cells 
which are found between the fibers as they are arranged in bundles. In 
sections stained with hematoxylin they take the stain deeply, and the 
fibers, which are unstained, are differentiated by the cells lying in rows 
between them. The number of fibroblasts in the membrane decreases 
with age. They are large and numerous in the membrane of a newly 









PERIDENTAL MEMBRANE. 



143 



erupted tooth, and comparatively small and few in the membrane around 
an old tooth. This is characteristic of fibroblasts in other positions. 
The fibroblasts are shown as they appear in a hematoxylin-stained 
section with low powers in Fig. 124, which gives part of the membrane 
in the gingival portion between two teeth. The cells are seen as spindle- 
shaped dots which mark out the fibers ; at F they are seen in a position 

Fig. 124. 




'^-F' 



Fibers and fibroblasts from transverse section of membrane : F, fibers cut transversely ; F 1 , fibers 
cut longitudinally, showing fibroblasts. (About 80 X.) 

where the fibers are cut transversely. With higher powers these cells 
appear as in Figs. 126 and 135. 

The cementoblasts are the cells which form the cementum, and are 
found everywhere covering the surface of the root between the fibers 

Fig. 125. 






Cementoblasts. (Drawing by Dr. Black.) 



which are imbedded in the tissue. While these cells perform the same 
function for the cementum as the osteoblasts do for bone, they are in 
form very different from the osteoblasts. The cementoblasts are always 
flattened cells, sometimes almost scale-like, and when seen from above 



144 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

are very irregular in outline. This irregularity of outline is caused by 
the cells fitting around the attached fibers of the membrane so as to 
cover the entire surface of the cementum between the fibers. Fig. 125, 
from a drawing by Dr. Black/ shows several cementoblasts as seen 
when isolated by teasing. The cementoblasts have a central mass of 
protoplasm containing an oval nucleus, and short irregular processes 
which fit around the fibers as these spring from the surface of the 
cementum. Fig. 126 shows them in section perpendicularly to the 

Fig. 126. 




Transverse section, showing the cellular elements : Fb, fibroblasts ; Ec, epithelial structures ; 
Cb, cementoblasts ; Cm, cementum ; D, dentin. (About 900 X-) 



surface of the root, where they are crowded between the fibers. The 
cementoblasts often have processes projecting into the cementum like 
those from the osteoblast, but processes projecting into the membrane 
have never been demonstrated. 

In the formation of the cementum occasionally a cementoblast be- 
comes inclosed in the formed tissue filling one of the lacunae, in which 
position it becomes a cement corpuscle. 

1 Periosteum and Peridental Membrane. 



PERIDENTAL MEMBRANE. 



145 



Fig. 127. 



H.B. 




Pd.B, 



Border of growing process : Cm, eementum ; Pd, peridental membrane ; Pd.B, solid subperidental 
and subperiosteal bone with imbedded fibers ; Ms, medullary space formed by absorption of 
the solid bone; H.B, Haversian-system bone without fibers; Per, periosteum. (About 50 X.) 
10 



146 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



The osteoblasts of the membrane cover the surface of the bone, 
forming the wall of the alveolus, lying between the fibers which are 
built into the bone. In form and function they are like the osteoblasts 
in attached portions of the periosteum. They form bone around the 
ends of the peridental-membrane fibers, building them into the sub- 
stance of the bone. The bone thus formed over the wall of the 

Fig. 128. 



Pd.M 




Pd.B. % 



H.B. 



r'enetrating fibers in bone : Pd.M, peridental membrane ; Ob 1 , osteoblasts of peridental membrane ; 
Ob-, osteoblasts of medullary space; Pd.B, solid subperidental and subperiosteal bone with 
imbedded fibers ; Ms, medullary space formed by absorption of the solid subperidental bone 
with imbedded fibers ; H.B, Haversian-system bone without fibers built around the medul- 
lary space. (About 200 X-) 

alveolus is like the solid subperiosteal bone, and is penetrated 
throughout its thickness by the imbedded fibers ; but, as with the 
subperiosteal bone, it is constantly being penetrated by perforating 
canals, the solid bone being removed by absorption and rebuilt in 
bone with Haversian systems. This process is shown in Fig. 127, 



PERIDENTAL MEMBRANE. 
Fig. 129. 



147 




Osteoclast absorption of bone over permanent tooth : Oe, osteoclasts ; B, bone of crypt wal 
F, fibrous tissue of follicle wall ; A, ameloblasts. (About 62 X.) 

Fig. 130. 




Osteoclasts: Oc, osteoclasts ; B, bone. (About 66 X.) 



148 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



a section through a growing portion of the process around a per- 
manent tooth. A higher power (Fig. 128) shows the penetrating 
fibers and the formation of Haversian-system bone without fibers, in 
the body of the process. 

The osteoclasts, or myeloplaques, are bone-destroying cells (Fig. 
129); they act not only upon bone, but also upon cementum and dentin. 
They are oval cells, often as much as 30 microns in diameter, and con- 
tain many nuclei, — from two or three to fifteen or twenty. They are 
often called giant cells. The osteoclasts are not constantly found in the 
membrane, but make their appearance whenever calcified tissues are to 
be destroyed. In order for them to act upon the tissues they must lie 
in contact with its surface, and therefore the first step in absorption of 
the peridental membrane is the cutting off of the fibers imbedded in 
the bone or cementum. Where the osteoclasts act upon the surface of 

Fig. 131. 




Record in the calcified tissue of an absorption repaired : D, dentin ; Cm, cementum filling absorp- 
tion cavity. (About 40 X.) 



the tissue they produce bay-like excavations, in which they lie, and 
which are known as Howship's lacunae. These excavations are shown 
in Fig. 132, though the osteoclasts have disappeared. In Fig. 131,. 
from a ground section, the basin-like excavations are shown filled with 
new-formed cementum, thus leaving in the tissue the record of an 
absorption repaired. In absorption of the roots of the temporary teeth 
the osteoclasts are found not only in the membrane and attacking the 
surface of the root, but all through the medullary spaces in the bone, 
removing the temporary alveolar process. 

When absorption is going on at one place on the surface of a root 
a compensating formation of cementum is going on at another, so 
that not all of the fibers of the membrane are cut off. This is illus- 



PERIDENTAL MEMBRANE. 



149 



trated by sections of temporary teeth that are ready to be shed (Fig. 
132). 



Fig. 132. 




Root of a temporary incisor, showing absorption and rebuilding of eementum (from sheep) : G, gin- 
givus ; D, dentin ; Cm, eementum ; Ab, absorption cavity, showing Howship's lacunse ; CW, new- 
formed eementum. (About 50 X.) 



EPITHELIAL STRUCTURES OF THE MEMBRAXE. 

The peridental membrane contains cellular structures of epithelial 
character which are so conspicuous that they demand consideration, 
though their nature and origin are not as yet fully understood. 

These structures were first well illustrated and described by Dr. 



150 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



Fig. 133. 



I u 



Diagram of glands of peridental membrane. (G. V. Black.) 
Fig. 134. 



Fb.- 




Ec. 



■Ec. 



Ec. 







Ob. 

Cm. 

-I). 



Epithelial structures of the peridental membrane (from sheep): Fb, fibroblasts; Ec, epithelial 
structures; Cb, cementoblasts ; Cm, cementum ; D, dentin. (About 468 X.) 



PERIDENTAL MEMBRANE. 



151 



Black, in his work on the periosteum and peridental membrane, in 1887, 
and were called by him the glands of the peridental membrane. About 
the same time von Brunn l described what are probably the same struct- 
ures, and which he regarded as embryonal remains of the inner layer 
of the enamel organ, which he described as growing down oyer the sur- 
face of the root. These structures appear as cords of epithelial cells 

Fig. 135. 




Epithelial structures (from sheep) : Fb, fibroblasts ; Ec, epithelial structures ; Cb, cemeutoblasts ; 
Cm, cementum ; D, dentin. (About 700 X.) 



arranged in the form of a network winding between the fibers of the 
membrane, very close to the cementum and surrouuding the root almost to 
the apex. Their arrangement is illustrated in Fig. 133, a diagram by Dr. 
Black. The meshes of the net are close in the gingival portion of the 
membrane, but grow more and more open in the alveolar portion. They 
are not confined to the membranes of young teeth or the temporary den- 
tition, as Dr. Black has shown them in the membrane of a tooth from 
a man seventy years old, though, like all of the cellular elements of the 

1 Archiv f. mikros. Anat , 1887. 



152 



DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 



membrane, they become less numerous as age advances. These struct- 
ures are specially well shown in the membranes of the pig and sheep. 
Fig. 134 shows their appearance in a transverse section of the root of an 
incisor of a sheep; here they swing out from the surface of the cemen- 
tum and back again in loops, winding in and out among the fibers. 
Studied with higher powers (Fig. 135), they are seen to be made up of 
epithelial cells, with large oval nuclei and reacting to the characteristic 
epithelial stains. They are arranged in cords, though sometimes what 
seems to be a lumen of a gland tubule can be found (Fig. 136). The 

Fig. 136. 





._<;& 



Eg. 



Epithelial structures : Ec, epithelial cord, apparently showing a lumen ; Cb, cementoblasts ; 
Cm, cementum ; D, dentin. (About 500 X.) 



cords are invested with a delicate basement membrane, but no special 
relation to bloodvessels has been demonstrated. The attempt to show 
their connection with the surface epithelium has thus far failed. As the 
gingivus is approached (Fig. 137), they seem to swing out from the sur- 
face of the root and are lost between the projections of the epithelium 
lining the gingival space. There is evidence that these structures are, 
at least in some cases, of importance as the primary seat of pathological 
conditions of the membrane. 



PERIDENTAL MEMBRANE. 
Fig. 137. 



153 




Longitudinal section: Ep, epithelium lining the gingival space; Gg, gingival gland, so called; 
D, dentin ; N, Nasmyth's membrane ; Du, duct-like structure stretching away toward the gin- 
givus from the epithelial cord, seen at Ec ; Cm, cementum, separated from the dentin by 
decalcification. (About 50 X.) 



154 DENTAL HISTOLOGY AND OPERATIVE DENTISTRY. 

Fig. 138. 



B, 



B. 







Cm. 



Pd. 



Om 1 



Fig. 139. 



B. 



B. 



Pd. 



Cm. 



D. 



P. 



Young and old membranes (from sheep) : D, dentin ; Cm, cementum ; Chi 1 , thickening of cemen- 
tum to attach fibers at the corner; Pd, peridental membrane ; B, bone forming the wall of the 
alveolus ; P, pulp. (About 80 X .) 



PERIDENTAL MEMBRANE. 155 

BLOODVESSELS AND NERVES OF THE MEMBRANE. 

Bloodvessels. — The blood-supply of the peridental membrane is 
very abundant. Several vessels enter the membrane from the bone in 
the apical region. These arteries branch and divide, forming a rich 
network, from which the capillary vessels are given off. The arterial 
network is constantly receiving vessels which enter the membrane 
through Haversian canals opening on the wall of the alveolus, and in 
this way the size of the vessels passing occlusally is maintained. Ar- 
terial vessels also enter the membrane over the border of the process. 
This double or triple supply of the membrane is important, as it main- 
tains the health of the membrane when the supply entering through 
the apical region is entirely cut off by alveolar abscess. While the 
arterial supply of the membrane is very rich, the capillaries in the 
membrane are comparatively few. This is, however, a characteristic 
of connective-tissue membranes. 

The nerves of the peridental membrane have not been sufficiently 
studied to be described in detail. Six to eight medullated nerve trunks 
enter the apical region in company with the bloodvessels, and they re- 
ceive other trunks through the wall of the alveolus and over the border 
of the process, but the manner of their distribution and the nature of 
their endings are not known. 

THE CHANGES WHICH OCCUR IN THE MEMBRANE WTTH AGE. 

When a tooth is erupted the roof of the bony crypt in which it was 
inclosed in the body of the bone is removed by absorption and the 
crown advances through the opening. The diameter of the alveolus at 
that time is, therefore, greater than the greatest diameter of the crown, 
and the peridental membrane which fills the space is very thick. By 
the formation of bone on the wall of the alveolus and the formation 
of cementum on the surface of the root the thickness of the membrane 
is reduced. In the young membrane most of the large bloodvessels are 
found in its outer half, forming a rather defined vascular layer near its 
centre. In the old membrane most of the bloodvessels are found very 
close to the surface of the bone, often lying in grooves in its surface. 
Both young and old membranes are illustrated in Figs. 138 and 139, 
which are taken from the temporary teeth of a sheep, one just after 
eruption and the other shortly before the time of shedding. 



CHAPTER IV. 

ANTISEPSIS IN DENTISTRY. 

By James Truman, D. D. S. 



The importance of antisepsis in dental operations has not been 
recognized as fully as the subject would seem to warrant. This has 
been in part due to the fact that dentists have been accustomed to the 
thought that cleanliness in the use of instruments would meet all the 
requirements of practice. This idea has been enforced by a general im- 
munity from unpleasant sequelae after operations, thus leading to a skep- 
ticism in regard to the value of antiseptic measures in the oral cavity. 
This immunity has been in part due to the fact that the fluids of the 
mouth were supposed to have a direct influence in preventing in- 
fection. This has never been proved through laboratory experiments, 
but clinical observation and long experience have demonstrated that 
injuries in the mouth ordinarily heal rapidly, even though these be made 
by infected instruments. It seems unreasonable to suppose that a fluid 
peculiarly subject to fermentation should have this effect, and this has 
led some to ascribe it to a vital influence. Miller l says of this : " It 
is a very fortunate provision that the gums in a healthy state offer so 
powerful a resistance to the invasion of the germs of most infectious clis- 
eases. For this reason a wound in the gums may be followed by 
scarcely any reaction whatever, while a similar wound on the hand 
with the same instrument may produce most disastrous results. It has 
been attempted to account for this fact on the supposition that the 
saliva has an antiseptic action, in evidence of which we are often re- 
minded that dogs lick their wounds, and that these heal rapidly. 
I doubt if there is anyone who would wish us to believe that 
the dead saliva has even the slightest antiseptic properties, in consid- 
eration of the fact that saliva, especially when it contains much organic 
matter, readily putrefies. If the saliva possesses any such property, it 
must be sought for in its living histological elements, — i. e., in the living 
leucocytes or phagocytes." 2 

1 Dental Cosinos, July, 1891. 

2 For an elaborate study of this problem see "Experimental Study of the Different 
Modes of Protection of the Oral Cavity Against Pathogenic Bacteria," by Arthur C. 
Hugenschmidt, M. D., Dental Cosmos, xxxviii., p. 797. 

157 



158 ANTISEPSIS IN DENTISTRY. 

While it is true that there exists a degree of exemption from serious 
results, leading to indifference and careless management of cases, it is 
equally true that infection has resulted in the experience of almost 
every operator in dentistry. 

Prior to the period when Lister announced that all operations in 
surgery should be performed antiseptically, and made modern surgery 
possible, this ignorance was excusable ; but at the present time, with the 
accumulated knowledge in bacteriology, it should be impossible for any 
dental operator to neglect the procedures under this head considered 
absolutely essential for the general surgeon. 

The difficulties attending antisepsis in dentistry far exceed those in 
other branches of surgery. The dentist is necessarily obliged to meet 
conditions hourly that seem to preclude absolute freedom from sources 
of contamination. If he were to take the same precautionary measures 
now regarded as necessary for the surgeon, he would find practice almost 
impossible. While this is true, it does not follow that every effort 
should not be made to approach absolute surgical cleanliness. 

The usual methods employed to accomplish this, while valuable to 
a limited extent, are by no means equal to what could readily be secured 
without consuming much time or patience. The dentist is usually sat- 
isfied that he has fulfilled all antiseptic precautions when he has dipped 
his instrument in some antiseptic fluid, generally carbolic acid. Little 
or no attention is paid to the possibility of infection from rubber-dam, 
towels, hands, and the variety of instruments that enter into dental 
operations. Some of the latter, as, for instance, the separator, are more 
liable to carry infection than the excavator, the one generally regarded 
as most important. 

The appliances ordinarily in daily use are the rubber-dam, excava- 
tors, broaches, pluggers, clamps, ligatures, separators, drills, hand- 
pieces, napkins, and forceps. It is safe to assume that but few of these 
will receive any attention beyond ordinary washing. The rubber-dam 
is too often used as it is furnished by the manufacturer. If an attempt 
at cleanliness is made, it consists in washing the dam in cold or warm 
water, this being regarded as sufficient. When it is remembered that 
this is passed between teeth and usually forced up under gingival 
margins with ligatures, or clamps, frequently lacerating the surface, it 
becomes evident that the possibility of infection is always present. 
If infection does not occur from the rubber, it is almost certain to pro- 
duce a wound in a locality extremely favorable for the growth of patho- 
genic germs. The result is innumerable lesions that may extend to 
pericemental inflammations. The great increase in the past twenty- 
five years of gingival inflammations subsequent to operations in mouths 
of more than ordinary health must be partly ascribed to this cause. 



SOURCES OF INFECTION. 159 

Excavators ordinarily receive the most attention, and yet, when their 
use is considered, they possibly require the least. It is rarely necessary 
to use the excavator outside of a cavity, where infection, if at all pos- 
sible, would do the least harm, for the continual washing of the cavity, 
as the operator proceeds, reduces the danger to a minimum. Broaches, 
and all instruments intended to enter the pulp canals, require the most 
careful attention, and this applies with equal force to drills ; yet it is 
feared that both of these, loaded though they are with septic matter, 
receive but indifferent care. When the dangerous possibilities which 
may result from this negligence are considered, it becomes a serious if 
not a criminal offence. The difficulty in making these instruments germ- 
free and in keeping them from becoming contaminated is fully appre- 
ciated ; yet the effort must be made, and it is not a difficult procedure, 
nor does it require a large consumption of time — an important item to 
the dental operator. 

Pluggers cannot be regarded as a source of infection. They are 
used solely in connection with metal, and therefore strict cleanliness 
is all that is absolutely required. It is fortunate that this is so, for 
•these instruments require unusual care to protect them from rust. 
Hence immersion in an antiseptic fluid is deleterious and not re- 
quired. 

Separators — and under this head are included metal with screw 
attachments and wedges — require special attention, but probably receive 
the least. They should be made as nearly sterile as possible before 
their use upon a patient. 

Hand-pieces, of the various kinds in use, are probably the most 
difficult to keep thoroughly clean. While they do not come in direct 
contact with the tissues of the mouth, they may indirectly, by contam- 
inating the hands, produce unpleasant results. Frequent taking apart 
and boiling are essential, and should not be omitted. 

Napkins from the ordinary wash have been and are used with con- 
fidence that no bad results from use can follow. If the laundry is con- 
fined to the home, this may ordinarily be true, but the indiscriminate 
mingling of washes indulged in by the commercial laundryman is 
always a menace to health. Where napkins of the latter character are 
to be used they should be subjected to the sterilizing process. 

The chair occupied by a variety of patients may be a source of 
disease, and should be carefully cleansed, especial care being taken with 
the head-piece. The latter should be covered with a clean napkin, to 
be changed for every patient. 

The cuspidor, where the fountain is not used, is ordinarily an abom- 
ination, for here, if anywhere, will carelessness be manifest. There can 
be no excuse for this, as thorough daily scalding with boiling water and 



160 



ANTISEPSIS IN DENTISTRY. 



the 



use of antiseptics will keep it measurably free from unpleasant 

consequences. 



Fig 




Downie steam sterilizer. 



Glasses require to be thoroughly boiled 
both before and after use. Boiling should 
never be neglected with ejector tubes, either 
metal or glass, glass being generally used. 
Hard boiling in water for twenty minutes 
should be sufficient. 

The lancet is an instrument demanding 
especial care, as it may become a danger- 
ous source of infection. Before it is used 
the adjacent portions of the gum should be 
washed with an antiseptic. 

The forceps employed in extraction 
should be so constructed as to render the 
blades readily separable at the joint, and 
they should be boiled in water and soda 
solution for an hour. The recorded cases 
of infection from these instruments render 
this care imperative in all instances. 

Fig. 140 shows a convenient form of 
apparatus for sterilizing ordinary dental 



instruments by boiling soda solution. 

Oral Diseases and Their Transmission. 

The possibility of carrying disease from one person to another seems so 
self-evident that it ought not to require more than a word of caution, 
and yet it is clear that the attention given to this source of danger is by 
no means commensurate with the risks assumed constantly in practice. 
The peculiarly transitory character of much of dental practice precludes 
the possibility of any previous history of patients, and therefore every 
one should be regarded as a possible source of infection. 

Diseases the result of pathogenic bacteria independent of possible 
external infection are now in the main well understood, but by no means 
equally appreciated by medical practitioners, nor are they properly con- 
sidered by dental operators. Miller 1 states that " many facts favor the 
supposition that a considerable number of pathogenic micro-organisms 
may thrive in the juices of the mouth without showing in their vital 
manifestations any distinction from the common parasites of the oral 
cavity as long as the mucous membrane remains intact. If, however, 
the soft tissues have been wounded, as in extraction, or if the resistance 
of the mucous membrane has been impaired, these organisms may gain 

1 The Micro-organisms of the Human Mouth, page 275. 



ORAL DISEASES AND THEIR TRANSMISSION. 161 

a point of entrance and thus become able to manifest their special 
actions." This fact, now well recognized, is being constantly demon- 
strated in the use of the various appliances that may, through careless 
handling, injure the mucous membrane. So much is this the case that 
a large proportion of gingival inflammations have undoubtedly had 
their origin from this cause. It has come under the observation of the 
writer that injuries thus received, although apparently unnoticed by 
i entist or patient, have resulted in the course of forty-eight hours in 
very disturbing pericementitis, confusing to the operator and very painful 
to the patient. The necessity for such antiseptic precautions here as are 
taken in general surgery is almost entirely overlooked. Before placing 
the coffer-dam, the clamp, or ligature, that portion of the mouth should 
be thoroughly washed with an antiseptic solution and an effort made 
to render the appliances equally sterile, or at least to inhibit develop- 
ment for a definite period. When the operation has been completed 
the same care should be extended to the tooth and contiguous structures. 
The evidence is abundant that many cases of pyorrhea alveolaris have 
had their origin from this careless indifference to accepted and necessary 
precautions. 

The mouth as a source of disease to the general system does not 
properly belong to this article to discuss, but its importance cannot be 
overlooked. Dental writers have devoted much attention to this sub- 
ject. It is for the dentist to understand that he is, to a large degree, 
responsible for the general health of his patient as far as the mouth is 
concerned, and he should insist on prophylactic measures that will at 
least reduce this source of disease to a minimum. The constant danger 
of what Miller aptly calls " auto-infection " from the collection and 
propagation of pathogenic bacteria in the fluids of the mouth should 
suggest to the dentist constant efforts to effect the removal of all deposits 
on the enamel, gingival margins, tongue, and mucous membrane. This 
line of study will bring about in the future an entirely different dentistry 
as to hygiene and prophylaxis from that practised at the present time. 

The pulp of a tooth is not ordinarily regarded as a point of in- 
fection, and yet it is well known to be a serious menace to the health 
of an individual. Israel, quoted by Miller, 1 asserts that " the root 
canal furnishes a point of entrance even for the ray-fungus, actinomyces, 
and in one case the microscopic examination revealed the elements of 
this organism in the canal of a pulpless tooth." When it is considered 
that some individuals have decomposed pulps in a number of teeth at 
the same time, and frequently a score of dead and broken roots, sending 
out their infectious material, it is not surprising that disease of a serious 
nature may supervene. While there is no record of cases coming 

1 The Micro-organisms of the Human Mouth, p. 285. 
II 



162 ANTISEPSIS IN DENTISTRY. 

within the observation of the writer of pulps producing pyemia directly, 
it is a well-known fact, supported by a long list of recorded cases, 
that alveolar abscess, with its concentration of putrid material, is liable 
to be followed by blood-poisoning. 

There is no question that diseases of the digestive organs, of the 
lungs — in fact, of all the organs of the body — may be produced by 
infected material germinated in the mouth, and indeed, through sputum 
ejected, may affect individuals remotely situated. 

Miller, 1 in considering this portion of the subject, says : " We know 
that under certain circumstances saccharomycetes may directly colonize 
in the mucous membrane of the mouth, and that in the mouths of 
enfeebled individuals bacteria may occasionally obtain a foothold. 
The mucous membrane of the mouth and pharynx is especially sus- 
ceptible to the action of certain germs of infection (those of diphtheria, 
syphilis, etc.), and large portions of the mucous membrane and the sub- 
mucous tissue may be wholly destroyed by parasitic influences." 

There is a phase of this subject that requires more extended in- 
vestigation. Inflammations of the mouth are not infrequent where 
great swelling is present. This may be observed around the lower 
third molars with no explainable cause in dead pulps, overlapping 
mucous membrane, retarded eruption, or mal-presentation. It is evi- 
dently produced by bacterial invasion, but has not always yielded to 
antiseptic measures, and at times has resulted in abscess entirely inde- 
pendent of pulp devitalization. 

A recent report of three cases by Dr. John A. McClain 2 in the 
medical practice of Dr. M. G. Tull is interesting as indicating possi- 
bilities. The first case was an extensive swelling posterior to the lower 
third molar. He could not connect it with that tooth, and suspected 
auto-infection. He had cultures made with negative results. His 
theory was that it was diphtheritic ; and, although laboratory evidence 
was wanting, he determined to inject antitoxin. This injection was 
followed in twenty-four hours by an entire reduction of the swelling. 
All other efforts had previously failed to effect any result. Two other 
similar cases yielded to the antitoxin treatment in the same speedy 
manner. If this can be regarded as something more than a coincidence 
in practice, it may lead to an explanation of many similar anomalous 
pathological cases arising posterior to the third inferior molar, yet 
apparently not connected with it. Similar conditions have been the 
cause of much uncertain diagnosis and still more empirical treatment. 

The more the writer has considered this subject the more important 
it has appeared; and he is convinced that, when the proper prophy- 

1 The Micro-organisms of the Human Mouth, p. 295. 

2 International Dental Journal, October, 1900. 



INFECTION FROM MOUTH TO MOUTH. 163 

lactic measures come into use for the prevention of tuberculosis, in all its 
protean forms, antisepsis of the mouth will be given primary importance. 

Infection from Mouth to Mouth. 

Infection from mouth to mouth through instruments is a difficult 
matter to prove by cases, but theoretically there can be no cause for 
disputation. The question will always arise, Was the lesion occasioned 
by auto-infection or by transmission ? The answer can rarely be given 
with the assurance desirable. In one instance, at least, in the writer's 
experience the origin was clearly traceable. This was in a patient of the 
better class, presenting for treatment in the clinic of the Dental Depart- 
ment of the University of Pennsylvania. Her teeth were remarkable for 
structure, regularity, and cleanliness ; gums perfectly healthy. Necrosis 
of the anterior alveolar plate was threatened when first seen, and 
finally resulted in the entire destruction of the alveolar border and all 
the anterior upper teeth, but did not involve the maxilla. The history 
of the case as given was that a bicuspid had been extracted from the 
right superior region by a dentist notorious for his uncleanly habits. 
Not long thereafter the patient noticed a serious inflammation. These 
symptoms indicated a syphilitic infection, and the family physician was 
consulted, who insisted that no history of this disease existed and that 
infection must be the cause. The patient, through his treatment and 
that given locally, recovered, but was forced to wear an artificial sub- 
stitute. 

Cases of infection through extraction, either by the forceps or after- 
infection from the mouth, might be quoted almost indefinitely. Miller 
reports case upon case — in fact, the accumulation of these has become 
of serious moment ; and yet, in the face of undisputed facts, dentists 
will continue to extract teeth frequently without any precautions, or, 
at most, relying on simple washing of the instrument. Some German 
writers contend that antisepsis after extraction is wholly unnecessary, 
as the clot formed is a sufficient protection. This is certainly not true 
in all cases. It is not always the fact that a clot is formed, or when 
formed that it serves an antiseptic purpose. One of the most serious 
cases that has fallen to the writer to treat was that of necrosis of the 
superior maxilla involving destruction of the right side, taking in all 
the teeth from the third molar to the lateral, the floor of the antrum, 
a portion of the nasal bones, and half of the hard palate. This was the 
result of the extraction of the third molar by a specialist before the 
days of antisepsis; whether it was the result of infection is difficult 
to determine. In the opinion of the writer, no extraction should be 
attempted until the instruments used have been thoroughly sterilized by 
boiling. Before the forceps are applied the parts surrounding the tooth 



164 ANTISEPSIS IN DENTISTRY. 

should be well washed with an antiseptic solution. After the extraction 
the socket should be syringed with sterilized water, followed by 
some powerful disinfectant. In view of the serious results probable in 
this operation there is no longer any excuse for injuries resulting from 
infection, and a suit for malpractice could be well sustained against an 
individual who had failed to observe the well-understood methods of 
antisepsis, while no intelligent practitioner could conscientiously appear 
on behalf of the defendant. 

External Infection. 

The danger to the operator from external infection from instruments 
is a constant menace; the constant use of these with general freedom 
from serious results, however, leads to a degree of carelessness not war- 
ranted by the ever-present danger from wounds. There is more real 
danger to the operator from this source than to the patient. All the 
excavators, drills, and broaches are hourly in contact with infectious 
matter, and it requires but a slight wound to produce any of the possi- 
bilities of blood-poisoning. The operator should be on constant guard 
in this respect, upon the slightest abrasion immediately taking measures 
to destroy all possibility of infection from germs that may have been 
introduced into the wound. This should at once be carefully washed 
and an escharotic employed, burning the parts. For this purpose zinc 
chlorid or carbolic acid is probably the best agent to use, followed by 
an antiseptic. The latter should be frequently renewed. Experience 
has demonstrated the value of turpentine in the various mechanical 
shops where this agent has been for many years in common use for 
wounds from rusted iron, the possibility of trismus resulting from such 
injuries being well understood. The writer has used this agent, after 
burning the wound, almost to the exclusion of other antiseptics. 

An illustration of the ever-present danger from wounds occurred 
to a friend of the writer's, one of the many young women who have 
graduated in dentistry in this country. She accidentally wounded her 
hand by a drill, and regarded it as of no moment. The result was severe 
blood-poisoning that for two years kept her hovering between life and 
death. After suffering from severe metastatic abscesses, she was finally 
restored to partial health, but with her constitution shattered and her 
practice ruined for the time being. 

Implantation and Transplantation. 

Previous to the recognition of the importance of antisepsis, the 
dentists of that period had a very natural objection to reimplanting 
teeth ; the practice of transplantation was then practically an unknown 
operation. The danger of the operation was appreciated, but the reason 



AGENTS USED FOR STERILIZATION. 165 

was not then comprehended. When the study of bacteriology had ad- 
vanced to a science through the labors of Pasteur, Koch, and a host of 
investigators, the reasons for this fear were explained, and the condi- 
tions necessary to avoid unpleasant results being understood, the danger 
from infection was changed to absolute security. It is, moreover, to be 
ever borne in mind that but for this knowledge implantation and trans- 
plantation could to-day not be practised without the probability of 
serious results. 

A case illustrating this point occurred prior to the knowledge of anti- 
sepsis in the hands of a well-known dentist. He had removed three 
teeth and successfully reimplanted them for the cure of a violent case of 
neuralgia presumably due to calcific depositions in the pulp and about 
the external portions of the roots. Relief was so immediate that upon 
return of the pain another tooth was attempted. Trismus followed, 
resulting in the death of the patient. It is safe to assume that this 
unfortunate result could not have happened under the antiseptic care 
usual at the present time, even imperfect as it frequently is. 

To accomplish antisepsis in this operation the greatest care is neces- 
sary. In transplantation, teeth being procured from other mouths, 
the danger is necessarily much increased. The method, adopted by 
some, of immersing these teeth in various antiseptic fluids cannot be 
commended. Miller says of this : l " It is generally accepted that 
the operator takes every possible precaution when he allows the tooth 
to lie for one-half to one hour in a 1 per cent, solution of carbolic acid, 
or in a 1 :1000 solution of bichloride of mercury. ... In order to 
reach bacteria that may have penetrated into the lacunas or chance vas- 
cular canals a much longer action of the antiseptic is necessary, and to 
be perfectly certain that we have accomplished our object we should 
have recourse to boiling water." 

Agents used for Sterilization. 

The possibility of injuring instruments has deterred dentists from 
using many of the agents recommended for the purpose of sterilization. 

Miller 2 made tests of various agents with indifferent results, with 
the exception of carbolic acid, trichlorphenol, and mercury bichlorid. 
The list tested included the following : 

Carbolic acid in 5 per cent aqueous solution and in pure form. 

Lysol in 5 per cent, aqueous solution. 

Trichlorphenol in 5 per cent, aqueous solution. 

Sublimate in 5 per cent, aqueous solution ; also in the strength of 
1 : 1000 of water. 

Benzoic acid in the strength of 1 : 300 of water. 

1 Dental Cosmos, July, 1891. 2 Ibid., page 520. 



166 ANTISEPSIS IN DENTISTRY. 

Potassium permanganate in 5 per cent, aqueous solution. 

Resorcin in 10 per cent, aqueous solution. 

Hydrogen peroxid in 10 per cent, aqueous solution. 

Saccharin in concentrated alcoholic and aqueous solution. 

/9-naphthol in 5 per cent, alcoholic solution. 

Pyoktanin in concentrated aqueous solution. 

Absolute alcohol. 

Antiseptin in 5 per cent, aqueous solution. 

Zinc sulfate in concentrated aqueous solution. 

The essential oils in 5 per cent, emulsions and in pure form. 

The three previously named, carbolic acid, trichlorphenol, and 
mercury bichlorid, were the only ones that gave any satisfactory 
results, and these only partially so. In regard to the rest, Prof. Miller 
says : " They all fall far short of those already mentioned. The 10 per 
cent, solution of the peroxid of hydrogen came next to carbolic acid, 
but is considerably inferior to it. The essential oils, in emulsions as 
well as in pure form, utterly failed to produce the desired action." 

The results obtained by Miller are not wholly in accord with those 
of some others. Charles B. Nancrede, M. D., in an article l gives a 
list of agents which have " proved most reliable clinically, can be resorted 
to in any emergency, or are peculiarly applicable to meet exceptional 
indications : " 

Marked Inhibition. Complete Inhibition. 

Mercuric chlorid 1 : 1,600,000 1 : 300,000 

Oil of mustard 1 : 333,000 1 : 33,000 

Thymol . . , 1:86,000 

Oil of turpentine 1 : 75,000 

Iodin 1 : 5,000 1 : 1,000 

Salicylic acid 1 : 3,300 1 : 1,500 

Eucalyptol 1 : 2,500 1 : 1,251 

Borax , . . 1:2,000 1:700 

Potas. permanganate 1 : 1,400 

Boric acid 1 : 1,250 1 : 800 

Carbolic acid 1 : 1,250 1 : 850 

Quinin 1 : 830 1 : 625 

Alcohol 1 : 100 1 : 12.5 

At the time these tables were prepared one agent not mentioned was 
practically unknown as an antiseptic, — formaldehyd, or in solution 
known as formalin. 

Dr. Elmer G. Horton, B. S., assistant in bacteriology, Department 
of Hygiene, University of Pennsylvania, undertook, at the request of 
Dr. Edward C. Kirk, a series of investigations with formaldehyd, 2 the 
results of which are given, omitting the details of experiments : 

1 "Treatment of Wounds: Antisepsis and Asepsis," Surgery by American Authors, 
Park, page 365. 

2 Dental Cosmos, July, 1898. 



AGENTS USED FOR STERILIZATION. 



167 



" We employed the gas generated by heating over an alcohol lamp 
a pastil which contained five grains of paraform. The lamp was placed 
in a tin box of nearly one cubic foot capacity . . . (Fig. 141). Among 
the instruments employed in the tests were various chisels, excavators, 
and burs. These were boiled, shown by cultural method to be sterile, 
then either dipped into bouillon cultures or infected from selected cases 
found in the operative clinic of the Department of Dentistry, University 
of Pennsylvania. After infection each instrument was placed in a sterile 
tube and kept at incubator temperature (37.5° C.) for three hours. . . . 
In a single test with moist instruments we found sterilization complete. 
After the infection and subsequent drying the tubes containing the in- 
fected instruments were separated into two lots, one to be subjected to 



Fig. 141. 




Schering's formalin sterilizer 



the method of disinfection and the others to be kept as controls, by 
which would be shown that no step other than the action of formalde- 
hyd destroyed the vitality of the germs. . . . After exactly ten or 
fifteen minutes, according to the experiment, the door was opened and 
the instrument quickly removed. . . . Each instrument (controls like- 
wise) was placed in a considerable amount of sterile bouillon and these 
cultures, together with the subcultures made from them, observed for 
at least one week. ... In all experiments a free growth developed 
from the controls. . . . The disinfection of instruments purposely in- 
fected in the clinics from cases of caries, pyorrhea, and gingivitis was 
satisfactorily accomplished in every case. . . . AVe conclude that infected 
dental instruments can be disinfected without injury in a closed space 
of less than one cubic foot, by an exposure of fifteen minutes to the 



168 ANTISEPSIS IN DENTISTRY. 

formalclehyd gas generated from a pastil containing five grains of para- 
form by heating the pastil over a proper alcohol lamp." 

In an article on the " Uses and Limitations of Formaldehyd in 
Dentistry," by Dr. F. W. Low, Buffalo, N. Y., 1 the effect of formal- 
dehyd gas is further given as shown by a series of experiments con- 
ducted by Dr. Thos. B. Carpenter, assistant bacteriologist to the Health 
Department of the City of Buffalo. Without entering into detail, the 
experiments consisted of two series, one of infected instruments and the 
other of clothing either of school-children, of nurses, or of the doctor 
in the presence of contagion, to determine whether they could be thor- 
oughly sterilized by placing theni over night in a wardrobe exposed to 
the fumigation of the lamp used. 

The conclusion of Dr. Carpenter was that "This apparatus can be 
relied upon, after an exposure of from ten to fifteen minutes, to destroy 
thin layers of the common, non-sporulating pathogenic organisms." 

In regard to the second series of experiments with clothing, he says : 
" It is evident, therefore, that twelve hours' exposure to the action of 
this lamp in a closet of 15.8 cubic feet capacity is sufficient for effec- 
tive surface disinfection, the most resistant pathogenic bacteria being 
destroyed." 

A third series of experiments was undertaken with scaling instru- 
ments taken from the instrument-cases from several operators, including 
that of Dr. Low. The result of this elaborate experimentation is thus 
summed up by the author : " Every set, except the one where the whole 
case was fumigated over night, produced some cultures ; but not one set 
developed a culture of pathogenic organisms." 

"The Low lamp consists of an asbestos-lined tray, or box, sup- 
ported on legs (A), with an opening in the bottom to admit the chim- 
ney of the lamp, the purpose of which is to conduct the fumes of the 
formaldehyd gas into the tray and upon the instruments it is desired 
to sterilize. 

"The working parts of the lamp are shown in the illustration. An 
ordinary alcohol wick is drawn into the wick tube. To place the lamp 
(-B) in operation fill it with wood alcohol, grain alcohol being incapable 
of generating formaldehyd. Adjust cone-shaped platinum coil so 
that it just touches the top of the wick. Light the latter; place on 
chimney, and after a few seconds' waiting blow out the flame. If the 
cone be in proper adjustment to the wick, it will be observed that the 
coil glows like a live coal, but there is no flame or dangerous heat. 

"Having the lamp in operation, as described, and the tray properly 
adjusted to set over it, as in illustration, instruments may be placed 
in the tray and allowed to remain for ten minutes, a sufficient time to 

1 Dental Cosmos, February, 1900. 



AGENTS USED FOB STERILIZATION. 



169 



effect sterilization. When taken out they should be wiped dry with a 
surgically clean napkin or towel. 

"To stop the fumigation going on in the lamp, remove the chimney 
and slide the cage high up on the tube, so that the platinum cone no 
longer touches the wick, then allow it to cool before replacing chimney." 

Fro. 142. 








Low's formaldehyd lamp : A, for dental use ; B, for household use ; C, locked cage for public places. 

While it is not difficult for the average dentist to use formaldehyd 
as a disinfectant, it will probably be considered a useless expenditure 
of time, and, therefore, boiling in water and soda for at least twenty 
minutes seems the more feasible and is equally certain in the results. 

The dentist who aims to keep only aseptic instruments should have 



170 ANTISEPSIS IN DENTISTRY. 

two sets in daily use. When through with one patient the instruments 
should undergo the boiling process in preparation for the next. At 
the close of the day all instruments used should be thoroughly 
boiled and dried upon aseptic napkins and placed in the case. The 
possibility of infection from tne latter must not be overlooked. The 
first and second set, therefore, used the next day for the first time should 
be either boiled again or each instrument dipped into an antiseptic fluid. 
For this purpose the writer prefers a strong solution of hydronaphthol 
(8 grains to the ounce of alcohol) to the carbolic-acid solution ordinarily 
used. With this care all danger of infection can be removed and the 
dentist relieved of all legal responsibility. 

The preparation of the hands previous to operations is most per- 
plexing to the conscientious operator, whether this be in surgery or 
dental practice. In order that dental operators may be able to arrive 
at definite conclusions in regard to what may be required of them in 
their daily work, the following quotation is given from JNancrede's 
article l on the care required in hospital surgical practice : 

" Sterilized water as hot as can be borne should be employed. This 
must, of course, be never cooled by the addition of any but cold ster- 
ilized water. . . . The nail-brush, best made of vegetable fiber, must 
be always carefully rinsed after use and sterilized by heat for each 
operation. . . . Although it is alleged that all soaps made by heat are 
sterile — indeed, that potash soap is an active germ-inhibitor in the pro- 
portion of 1 : 5000 — yet it is the part of prudence to combine with the 
soft soap 5 per cent, of hydronaphthol or thymol, to insure that the 
soap itself is free from germs. After thoroughly rubbing into the hands 
and arms and under the nails abundance of soap, the nail-brush and 
hot water must be vigorously used, especially beneath and around the 
nails, for from two to five minutej. Next, carefully clean the nails and 
around them with a nail-cleaner. Removal of all grease can now be 
effected by ether or by immersion in alcohol, or best by alcohol contain- 
ing 5 per cent, of dilute acetic acid, which should be rinsed off thor- 
oughly with sterilized water, removing the last traces of soap. Finally, 
the hands should be immersed — not merely dipped — in a 1 : 2000 mer- 
curic chlorid solution for not less than three — preferably five — minutes. 
Instead of corrosive sublimate solution, ordinary mustard flour mixed 
in the hands into a thin paste with sterilized water, used with gentle 
friction for two or three minutes and then removed with sterilized 
water, will prove a most successful germicide." 

While the foregoing may serve as a basis for comparison, it would 
be wholly impracticable in dental practice. It remains, however, that 
the hands of the dental operator should be the subject of constant care. 

1 Loc. cit. 



AGENTS USED FOB STERILIZATION. 171 

Nails should be kept short and scrupulously clean. It seems to the 
writer that the use of a good potash soap and nail-brush, with bathing the 
hands in alcohol, will be amply sufficient unless working on a syphilitic 
patient, when more effective methods must be resorted to, and there can 
be nothing better than the mode described by Dr. Nancrede. 

The conclusions to which the writer has arrived from experience and 
study of the subject may be summed up briefly as follows : 

1. Dipping instruments in an antiseptic fluid previous to operating, 
while beneficial, is not sterilization. 

2. That boiling with soda is for the dentist the most convenient 
means of sterilizing instruments without injury, while the more recently 
introduced method of formaldehyd antisepsis is a dry process that does 
not rust or injure steel instruments and is also promptly effective. 

3. That the ordinary methods used to effect sterilization in surgical 
practice are not possible in dentistry, but that every dentist is legally 
and morally bound to live as near to the rules of antisepsis as is possi- 
ble with the demands of a daily practice. 



CHAPTER Y. 

THE EXAMINATION OF TEETH PRELIMINARY TO OPERA- 
TION—METHODS, INSTRUMENTS, APPLIANCES— RECORD- 
ING RESULTS, ETC. 

By Louis Jack, D. D. S. 



The Operator. 

The attitude of the body of the dental operator has considerable 
influence upon the ease. with which the various positions required in 
operating may be assumed, and also has some bearing upon the free- 
dom of his hands. 

The erect position should be maintained as far as possible and the 
preponderance of the weight should be sustained upon the balls of the 
feet. This secures equilibrium and enables movements to be made 
with little embarrassment. The shoulders should be held well back in 
order that the arms may not be cramped, and to permit the respira- 
tion to be carried on deeply and with quietness. For obvious reasons 
the breathing should be deep, slow, and always through the nose. 

The precise use of the fingers requires that in each application of the 
instrument a rest, as a fulcrum or base of action, should be used, and 
when force is to be applied a guard in addition is necessary to give 
security to the movement of the hand. The positions of the rest and 
the nature of the guard required in operating are various, depend- 
ing upon the situation of the territory of operation and somewhat 
upon the natural tact of the individual, so that a definition of 
them is scarcely required. Upon a careful application of the rests 
and guards depends the graceful and comfortable use of the instru- 
ments, and by means of them the hand passes by quick and easy grada- 
tion from the most delicate touch to the safe exhibition of considerable 
force. Each student should study and practice the use of the various 
rests and guards until by repetition their employment becomes invol- 
untary and appropriate to the situation. 1 

The contact with the patient should be at as few points as possible 
and should be generally made with the fingers. 

Examination of the teeth and mouth in all their particulars is a 

1 To aid in this study see American System of Dentistry, vol. ii. p. 44 et seq. 

173 



174 EXAMINATION OF TEETH. 

necessary preliminary to the treatment of any diseased or disturbed condi- 
tion which may appear. The importance of this procedure cannot be 
overestimated, as on it depends the formation of a correct diagnosis 
of departures from the normal state and it becomes a basis for the 
formulation of plans for the treatment required to restore the teeth and 
the related structures to a state of health, as well as to define the order 
in which the several operations shall be taken up, since an orderly pre- 
cedence in the treatment of individual teeth is frequently necessary. 

It is essential that the examination be most thorough, to prevent any 
failure to notice the least defect; since an unobserved slight lesion may 
become a deeper injury in a few months, and the consequences of an 
oversight may prove serious. 

Appliances used in Examination. 

The appliances required to effect thorough observation of every 
portion of each tooth to ascertain the extent of any lesion are of several 
kinds, viz, mirrors, magnifying glasses, explorers, floss silk, and wedges. 

The mierors should be both plane and concave. The plane mirror 
is important as a means to assist by the reflected image in determining 
the position of defects ; the concave as an adjunct to effect illumination, 
as it concentrates the rays of light and also may be used to produce an 
enlarged image. The enlarged image, however, is less sharp in defini- 
tion than the image of the plane mirror. 

Working to the Image. — The plane mirror is an important adjunct in 
all operative procedures connected with the teeth. Many situations in 
the mouth do not permit the direct reflection of the rays of light to the 
eye without assuming positions of the body and of the head of the 
operator which are awkward and embarrassing to free movement of the 
hand, as well as necessitating inconvenient and tiresome positions of the 
head of the patient. In addition, it frequently is impossible to secure 
correct observation of the progress of various procedures by direct 
vision. These difficulties may be overcome by the movements of 
the hand being directed by the image of the field of the pro- 
cedure on the mirror. This method of working to the image is at first 
difficult to the novice, since the images are reversed ; but by continued 
effort it becomes as easy to make correct application of movements by 
this method as by the direct rays of light. Further continued practice 
in this way renders the movements so completely under reflex control 
that the operator passes from a direct movement to a reverse one, and 
the contrary, without an apparent effort of the brain. This is equally 
true in all the various movements, even of those where the employment 
of considerable force is required. 



APPLIANCES USED IN EXAMINATION. 



175 



Fig. 145. 

h r 

a- 



The Quality of the Mirror. — These appliances should constantly be 
in good condition to insure clear definition in the image. The best 
kind of glasses are those in which the surface is covered by a deposit of 
F 144 pure silver. This furnishes a better reflect- 

ing surface and is more durable than is the 

so-called " silvering " with tin and 

Fig. 146. 
mercury. 

Magnifying lenses of about 7^ 

four diameters are useful to de- 7 

tect minute defects either in the 
teeth or in the condition of pre- 
vious operations upon the teeth. 
They are used either directly to 
magnify the parts, or else to mag- 
nify the image shown on the face 
of the plane mirror when direct 
rays of light cannot be caught. 
The latter method gives a clearer 
definition than the magnified image 
of the concave mirror. 

The magnifying glass may be 
the ordinary watchmaker's glass 
held before the eye by the muscles 
of the brow and cheek 
or the lens mounted 
as shown in Fig. 144. 
Such glasses are indis- 
pensable to the careful 
practitioner, since with 
their aid defects of the 
teeth and of operations 
may be detected which 
would escape obser- 
vation by other means. 

Explorers are, es- (j 
sentially, prolongations 
of the fingers ; they 
convey impressions by 
their vibrations to the Explorer, 
tactile nerves, and are principally intended to be 
applied to parts where direct rays of light cannot reach. The forms 
required are simple and few. Their points should be delicate, to enable 
the smaller apertures and spaces to be entered, and are best when made 




Magnifying lens. 



Self-contained 
socket. 



176 



EXAMINATION OF TEETH. 



of piano-wire, No. 18 B. & S. gauge, filed to acuteness 
and bent to a shape similar to that shown in Fig. 145. 
This form may be applied to all surfaces of the teeth, 
and but slight modifications are needed to explore posi- 
tions difficult of direct approach. At part a the size of 
the finer ones should be No. 25, and near the ultimate 
point, 6, No. 30. The temper of this kind of steel gives 
sufficient stiffness and also permits slight bending to make 
modifications of the form to meet all requirements. The 
ultimate point may be sharpened and renewed at pleasure. 
The handles in which these instruments are inserted may 
be of wood, with metal sockets which should be of sufficient 
length to come into contact with the finger ; or they may 
be fixed in metal holders, in which case the latter should 
be tapered to avoid weight and to give balance. Either 
form of handle should be round, to permit fractional 
rotary change of direction. Fig. 145 shows an explorer, 
which consists of a socket, into which the wire point is 
secured by means of powdered shellac or powdered sulfur. 
The points may be displaced and renewed when required. 
This socket fits into the usual cone-socket handles. Fig. 
146 is a self-contained socket for the same purpose. 

Explorers of this kind may be re-formed by straight- 
ening and then re-dressing between two emery-cloth disks 
in the dental engine, when the points can be shaped at 
will. 

Floss silk is used to pass between the approximal 
surfaces of the teeth at the places which are in too close 
contact to permit the ingress of fine explorers. In these 
positions floss silk may detect the presence of superficial 
softening of the enamel by the character of the friction 
or by the fraying of its fibers. It 
also is of use in determining the con- 
dition of fillings on approximal faces 
or the presence of a deposit of sali- 
vary calculus at similar parts. The 






Dow electric lamp for mouth illumination with reflectors. Reflector A is jointed to vary the angle 
of reflection. Reflector B is for illumination of the fauces. Reflector Cis for lateral illumination. 



THE EXAMINATION. 177 

silk should be slightly waxed in order to bind the fibers. Entire 
reliance cannot be placed upon the use of silk, since it may in some 
cases pass slightly carious spots without the fibers being displaced, but 
it frequently furnishes indications for further procedures by which to 
establish certainty as to the state of approximal surfaces. 

Wedges are used when neither explorers nor silk give positive indi- 
cations of carious action but have raised doubts of the integrity of any 
part. They may be of wood where the teeth are not firmly fixed, when 
the space may be immediately made ; otherwise, where the fixation is 
firm, india-rubber or linen tape may be forced in. 

Transillumination of the teeth and of the adjacent parts by the elec- 
tric mouth lamp (Fig. 147) is extremely useful in cases where a question 
has arisen as to the condition of any approximal surface. Superficial 
changes of the enamel may frequently be detected by this means. It 
is also of service in diagnosis of derangements of the antrum and to 
test the vitality of the pulp. 

The Examination. 

The parts of the teeth most liable to carious action are those 
which most easily retain deposits of sedimentary matter composed of 
food debris, thickened mucus, and bacterial growths. These are the 
labial and buccal surfaces, where the mechanical relations of the lips 
and cheeks tend to retain sediment ; the sulci, which by the direct 
force of mastication have food driven into them ; and the approx- 
imal surfaces. The latter are the most important to consider. 
The interproximal space is a serious predisposing cause of caries, be- 
cause the counteraction of the tongue and cheek in adapting the food 
between the occlusal surfaces of the teeth forces the finer particles of 
the food into the interproximal spaces, where it is retained by capillary 
attraction and by the apposition of the cheeks with the buccal surfaces 
of the teeth. This space is usually triangular, the gum forming the 
base of the triangle. The point where caries usually begins is at the 
apex of this triangle, where there is the least movement and inter- 
change of the contents of the space, as here the capillary force is the 
greatest, so that the fermentative processes of food decomposition are 
least interfered with. 

The technique of examination is as follows : After a cursory in- 
spection of the denture with the mirror, the explorer is applied to the 
previously indicated surfaces, particular care being used in determining 
the , condition of approximal surfaces, by introducing the instrument 
into the triangular space, the point being directed toward the acute 
angle. It should be drawn back and forth with a slight rotary move- 
ment so as to impinge the point successively upon the whole approxi- 

12 



178 EXAMINATION OF TEETH. 

mal surface of each tooth. This movement should be made from the 
inner as well as from the outer aspect. In this manner the instrument 
will be brought into contact with every accessible portion of the inter- 
proximal surfaces. 

Then the sulci are explored and the buccal and lingual surfaces 
examined. 

The inspection is thus conducted from tooth to tooth. Next the lines 
of apparent contact are critically tested with the mirror for evidence of 
slow changes of structure as shown by discoloration or rapid alterations 
shown by a milk -like appearance of the tooth surface. 

Finally, all approximal surfaces which could not be explored are 
silked. To do this the floss is wrapped upon the index finger of the 
left hand, and with the right is drawn between the contact surfaces 
with a sliding lateral movement. Care should be exercised that no 
injury be done to the gingival margin of the interproximal space by 
suddenly and forcibly driving the floss into contact with it. This acci- 
dent may be effectually avoided by a proper guarding and supporting 
of the fingers by contact with the adjacent teeth. Practice gives 
facility in determining by means of the silk the state of the parts in 
contact with it. 

In the inspection of previous stoppings, all margins, particularly 
those beneath the gum, should be critically inspected. 

Lastly, doubtful situations should be noted for subsequent examina- 
tion to be made after separation. 

(The tests for pulp exposures are considered in Chapters VII. and 
VIII.) 

The order of examination is best conducted by beginning at the 
median line of each quarter of the denture, progressing posteriorly with 
one line of observation and returning to the place of beginning with 
another line of observation. 

The Chart Record. — The chart record should at the same time be 
carried on by the principal, or better an assistant, with the view of 
securing a complete record of each derangement, for guidance and for 
reference. The details of the record are indicated in a simple manner 
by symbols which are illustrated by Fig. 148, and explained by the glos- 
sary. These symbols may be combined, where required, to give fuller 
expression. 

From this temporary record important operations when executed 
may be transferred to a permanent record. 

The constitutional condition and the texture and apparent resistance 
of the teeth to caries and attrition ; the inherited tendency to diseases of 
the teeth ; the chemical reaction of the mucous and salivary secretions ; the 
state of the general heath ; the condition of the mucous membrane of the 



THE CHART RECORD. 



179 



mouth and throat ; the indications presented by the tongue ; the dietary 
habits and other hygienic relations ; the tendency to catarrhal affections ; 
the presence of the rheumatic or gouty diathesis — are all questions which 



Fig. 148. 




S-EX 



signifies : In the interproximal space. 

/ " Attention— re-examine. 

// " Superficial softening. 

/// " A carious cavity. 

• " At the cervix. 

s " To separate. 

p " To polish. 



c signifies : Salivary calculus. 
ex " To examine. 

— 1 " A pulp nearly exposed. 

1 " A pulp probably exposed. 

3 " A pulp fully exposed. 

D " A devitalized pulp. 



enter into the prognosis and frequently largely determine not only the 
hygienic directions to be given to the patient, but also determine, in 
connection with the age and habits, the important question as to whether 
the restorative operations shall be of a permanent character or only of a 
temporary nature designed to preserve the teeth until restored normal 
functions may make it judicious to perform more enduring operations. 

The foregoing considerations with respect to the examination of the 
mouth and teeth sufficiently meet the requirements for beginning the 
rational treatment of dental disorders. 



CHAPTER VI. 

PRELIMINARY PREPARATION OF THE TEETH— REMOVAL OF 
DEPOSITS AND CLEANING OF THE TEETH— WEDGING— 
OTHER METHODS OF SECURING SEPARATIONS— EXPOS- 
URE OF CERVICAL MARGINS BY SLOW PRESSURE, ETC. 

By Louis Jack, D. D. S. 



Cleansing the Teeth. 

Before restorative operations are commenced upon the teeth all 
deposits of salivary calculus upon them should be removed and they 
should be cleansed of the covering- of partially inspissated mucus 
which even in persons of more than ordinary carefulness is liable to be 
found upon them. This film favors the admixture with it of sedi- 
mentary matter from food substances and frequently has so much con- 
sistence as to offer considerable resistance to its removal, and it pre- 
vents to a degree the contact of the naked brush with the teeth. Its 
presence is in every way detrimental to the preservation of the teeth, 
since it not only favors the adhesion of starchy matters, but also fur- 
nishes, wherever situated in connection with these food products, a 
favorable habitat for the development of bacterial forms responsible 
for the formation of the acid products that are the active agents of 
enamel solution. This deposit is most frequently formed on the inner 
and outer surfaces of the posterior teeth, where it invades the inter- 
spaces and in some cases covers all surfaces which are not directly sub- 
ject to the friction of mastication. It should be thoroughly removed 
and all surfaces should then be carefully polished. 

The best means to effect this is to polish the parts with a mixture 
of pulverized pumice with glycerin. The glycerin binds the particles of 
pumice and permits its retention upon the polishing instruments. The 
persistence of the deposit is shown by the fact that when the pumice 
is applied it is a moment before the polishing implement comes into 
actual contact with the enamel. To be suitable for this purpose the 
pulverized pumice should have been elutriated or passed through a fine 
bolting cloth to remove the coarse and irregular particles which if per- 
mitted to remain might cause injury to the enamel surface. After the 
removal a vitreous surface should be given by quick friction with stan- 

181 



182 



PRELIMINARY PREPARATION OF THE TEETH. 



Fig. 149. 



nic oxid (" tutty powder "), which also is better applied when combined 
with glycerin or rubbed up with vaselin. 

Salivary calculus is found precipitated at parts not subject to free 
friction, such as the buccal surfaces of the molars, the inner faces of 
the lower incisors, and it frequently invades the interstices. These 

deposits also should be displaced and the 
surfaces polished. 

The better appliances for the removal 
of superficial calculus are sickle-shaped 
scalers of various sizes and forms, which 
are inserted beneath the free margin of 
the gum, when the direction of the move- 
ment should be obliquely toward the 
occlusal aspect to avoid injury to the 
gingival attachment with the tooth. The 
consideration of the removal of deeply 
seated salivary calculus where some 
serious injury has been caused by its presence is treated of in Chap. 
XIX. 

Polishing" the Triangular Portion of the Interproximal Spaces. 
— When this is required an efficient means is to employ gilling twine 
of sizes proportioned to the space. This is applied by looping one 
or more strands with a piece of floss silk, when the silk is drawn up- 
ward into the triangle and then is used to pull the twine into the 
space, which being armed with suitable powders is drawn to and fro 
until the absence of friction indicates that the surfaces have become 
smooth. 




Abbott's scalers. 



CARE BY THE PATIENT. 

Coincident with the preparation above described the patient should 
be given such instruction as will tend to maintain the state of cleanli- 
ness. The importance of this should be impressed as a necessary 
hygienic measure to preserve the teeth. This is to be accomplished by 
the use of suitable brushes and properly compounded powders. The 
detergent effect of powder is principally due to the particles becoming 
mixed with the film of mucus. This action breaks up the continuity 
of the film, which, with the accompanying sediments, is displaced by 
the friction of the brush. 

The correct use of the brush requires that it be placed with some 
degree of firmness upon the outer and inner faces of the teeth and then 
slightly rotated. The pressure drives the bristles into the valleys, and 
the rotary movement being away from the gum avoids injury to that 
structure. The application of this procedure in combination with the 



TREATMENT OF THE MUCOUS SURFACES. 183 

use of j^'c&s and floss silk should maintain a correct hygienic condition 
of the teeth, upon which, in the light of the present knowledge of the 
causes of solution of the enamel, depends the preservation of the teeth 
from that source of injury. It has been shown that when sound 
enamel becomes attacked, the potent cause is the fermentation of 
starchy deposits permitted to remain in contact with it. 

It should be understood that the use of the pick removes deposits 
from the cervical triangle, and that silk is intended to sweep the more 
contracted portion of the interstice. 

Further reason for care is found in the fact that the mouth in an 
unclean condition becomes a favorable habitat for the development of germs 
some of which may have pathogenic properties capable of affecting the 
general health. It therefore becomes the duty of the dental adviser to 
enforce correct hygienic conditions of the mouth. 

Much importance in this connection should be attached to the use of 
cleansing preparations having inhibitive action toward bacterial life. 
Those most serviceable contain hydronaphthol, which has considerable 
efficiency without toxicity. Formalin as an ingredient of a wash is also 
applicable, but must be prescribed with considerable caution. 

Treatment op the Mucous Surfaces. 

When the gums, the membrane of the mouth or of the throat are 
inflamed, treatment preparatory to operations upon the teeth should be 
directed toward restoring these parts to a normal state. Where the 
inflammatory condition is not expressive of derangement of the alimen- 
tary functions and is the result of some simple local irritation, the 
condition will usually respond to the topical action of stimulant tonics. 

It is necessary here to discriminate as to whether or not the inflamed 
surface has been produced by neglected care of the mouth, which fre- 
quently induces a lax condition of the gum from the absence of friction 
or by the presence of bacteria. These may cause a deficiency of tone 
or disorders in other portions of the mouth and of the throat. Should 
these conditions be present the employment of disinfectant gargles and 
mouth-washes is indicated. 

The presence of salivary calculus may also induce inflammatory dis- 
turbance of the gums, and from the points of deposit this may extend 
by diffusion over a considerable area. In this connection deposits, 
either of calculus or of sedimentary accumulations, posterior to the lower 
third molars may induce serious diffuse inflammation of the contigu- 
ous tissues, sometimes extending to the fauces. For this condition the 
mechanical removal of the deposits combined with an antiseptic spray 
will usually be restorative. 

For diffuse redness and deficient tone of the mucous surfaces a wash 



184 PRELIMINARY PREPARATION OF THE TEETH. 

composed of potassium chlorate and quinin will prove sufficient in most 
cases, as follows : 

]fy. Potassii chloras, 3ij ; 

Quininse sulphas, gr. iij ; 

Sp. rectificatus, Ij ; 

Aquse, ^vj. — M. 

S. For use as a gargle. A dessertspoonful to a wineglass of 

water, or directly upon the gum in full strength by means of 
a soft tooth-brush. 

Concurrently with the local therapeusis the employment of massage 
of the gum with the finger, either naked or covered with a napkin, is 
of considerable value. 

When the conditions are catarrhal or are expressive of gastric 
derangement only general treatment with concurrent attention to the 
diet and correct hygienic relations will meet the requirements of the 
case. Coincident with the general treatment above indicated, the 
simpler operations upon occlusal surfaces may be carried on. 

In all cases of initial treatment for children or nervous patients it 
is important to begin with simple and, as nearly as may be, painless 
operations, to accustom such patients to the more or less disagreeable 
procedures and to elicit their interest and co-operation in what is being 
done for their benefit. 

Cavities on Approximal Surfaces. 

The preliminary treatment of this class of cases, on account of the 
limitation of space and the necessity for somewhat indirect application 
of the instruments and of the requisite force, necessitates the closest 
attention to every detail. Upon the care here taken depends the 
comfort, and furthermore, indirectly in many instances, the health of 
the person. 

The procedure of first importance is to produce a sufficient enlarge- 
ment of the interproximal space. In all cases, whether the teeth are in 
apparent contact or whether they may, from loss of substance on the 
approximal aspect, present sufficient room for the management of the 
various procedures, spacing is equally necessary. It is done in order 
that when the stopping procedures shall have been completed the natural 
relations of the teeth with each other will be restored. This relation, as 
before indicated, is one of apparent contact near the occlusal surface 
with a triangular space at the cervix. The mechanical basis of this 
arrangement is such that the function of comminution of food is better 
effected if there is no breach in the continuity of the occlusal aspect of 
the denture. 



SEPARATION OF THE TEETH. 185 

The consequences of breaches of continuity, especially in relation to 
the posterior teeth, are often of serious import. Not only may the food 
be driven into the space, to the discomfort of the patient, but serious 
injury of the gum may follow, as in many cases the tissue becomes 
inflamed by the impaction of food in the enlarged interspace, which in- 
duces peridental disturbances and may occasion the ultimate loss of the 
affected tooth. It is also not unimportant to consider that the forms of 
the teeth have an esthetic value, and that the harmony of the features 
forbids the mutilation of their natural forms. 

Separation of the Teeth. 

Separation of the teeth is a procedure requiring care to avoid injury 
and to render the process comparatively painless. 

When the teeth are mobile, as in the case of children, the movement 
is more easily and more quickly made than when the alveolar walls are 
compact and when also the teeth are in close proximity. In the former 
case the arch easily expands and permits the teeth to yield ; in the other 
case the resistance requires more force to be used and the application 
of it for a longer period. In all instances the force and the material 
used should be adapted to the presented conditions and the movement 
should be sustained until the required space is gained, it being dele- 
terious to make repeated attempts to separate the same pair of teeth. 
When the proper precautions are taken there is no danger attending 
the process ; even the firmest structures of mature age permit sufficient 
spacing if it be slowly and steadily done. 

METHODS OF MAKING SEPARATIONS. 

The means by which these are effected are various and the choice is 
determined by the amount of space required, the time in which it must 
be accomplished, and the firmness of the supporting structures. Some 
regard must also be had for the peculiar susceptibilities of the patient 
to the pain which may be caused by the effort. These methods are — 
by immediate wedging, which may be made when the fixation of the 
teeth is not firm ; by the swelling of firmly impacted pellets of cotton 
or of tape, and by the resilience of strips of caoutchouc where the teeth 
are in general contact and where they are firmly fixed. 

Immediate -wedging" is more applicable to the front teeth, where 
usually only a small space is required, and is a valuable method of 
securing a separation of the front teeth to determine their condition 
and to permit polishing strips to be inserted for the removal of super- 
ficial discolorations and for the treatment of superficial softening. Here 
the procedure is to insert a wooden wedge between the incisors near the 
incisive edge, when it is forced by pressure or by percussion until a suf- 



186 



PRELIMINARY PREPARATION OF THE TEETH, 



ficient opening is effected, the space then being secured by another wedge 
of hard close-grained wood forced between the teeth at the cervix. This 
process in some instances is repeated by forcing farther the first wedge 
and again increasing the security by driving the cervical wedge. This 
plan is not applicable when the interspace at the neck is quite angular, 
since the fixing wedge cannot be made secure, as it then is disposed 
to advance against the gum. In this case one of the subsequent 
methods should be pursued. 

If the fixation of the teeth be not firm they yield by a slight enlarge- 
ment of the arch and by closing the neighboring slight spaces. 

Immediate separations may be effected by mechanical separators, 
notably the William A. Woodward (see Fig. 150), for the front teeth and 






Fig. 150. 



Fig. 151. 






BretTfE 




Woodward's separator. 



^ii;;Bi;;ii,;il|ininfi^^||p^ 

Perry's separator in conjoint use with matrix. 



the Perry (see Fig. 151) for the bicuspids and molars. It should be 
stated that each of these is preferably to be used when some previous 
space has been made by other means, following which a considerable 
increase of space may be secured by these appliances. 

Separation by the Swelling- of Fibrous Materials. — These act by 
the capillary force of water upon the fibrous structure of the material, 
whether pledgets of cotton or tape. This means is also more applica- 
ble when the fixation of the teeth is not firm, and has the advantage of 
being painless and more readily tolerated by children and by persons 
who are impatient of pain or of any form of dental distress. 

Pledgets of cotton are more applicable where a partial preliminary 
opening of a carious cavity has been made, and are more appropriate for 
the posterior teeth. Here, when there is no danger of pulp exposure, 
the pledgets may be packed with considerable firmness. In some 
instances it is advantageous to saturate the pledget with thin sandarac 
varnish, which attaches the fibers, but the time required is much in- 
creased, as the cotton yields to capillary attraction only as it loses the 
resin. 

Tape is more useful for the incisors ; it should be of linen and may 
or may not be waxed. Its entrance is facilitated by an immediate pre- 
liminary application of a wooden wedge. 



SEPARATION OF THE TEETH. 187 

Caoutchouc — India-rubber. — When a strip of india-rubber is 
drawn into a close interspace the middle portion is constricted to great 
tenuity. The action is by the resilience determining the two exposed 
ends toward the middle, with the result that at length the space attains 
the size of the thickness of the strip. It will be perceived that the 
physical force is that of two opposed wedges acting with constant 
power. The effect is such that it overcomes the greatest resistance to 
separation of the parts and therefore is the most effective means which 
we have. 

Caution is required in the use of this material both as to the thick- 
ness of the rubber and as to its parity. The pronounced resilience of 
pure rubber is generally painful, and in most instances greatly so. 
The resilience can be reduced by employing adulterated specimens 
of the material. The white-rubber tubing of the shops cut longi- 
tudinally into various widths effects the object with less rapidity but 
surely, and generally without pain. The strip is drawn into position 
by a sliding motion, care being taken not to force the piece into contact 
with the gum. To prevent the rubber being conveyed to the gum as 
the space enlarges, a small portion should extend slightly beyond the 
occlusal surface. As this kind of rubber is more difficult to introduce 
when the contact is close and firm, a previous partial opening should be 
made with a piece of rubber dam. This method has the value of pain- 
lessness, and also does not usually necessitate a period of rest after the 
separation has been effected. 

Red Base-plate Gutta-percha. — When it is desirable to gradually 
effect considerable spacing between teeth, where the carious cavities are 
deep with well-defined boundaries but not involving the pulp, the method 
of Dr. Bonwill, of packing the cavities and the existing space with a 
sufficient mass of this form of gutta-percha, produces expansion by the 
continued force of mastication driving the material upward. This 
method also has value in some instances where it is desired to force 
the gum beyond the cervical margins, and may be an acceptable sub- 
stitute for aseptic cotton for this purpose. 

Securement of the Space. — Should soreness of the teeth have been 
caused by the separation, a period of rest should be given the parts until 
the distress has passed over. It is, however, important that large spaces 
should not be long retained, since in some instances alveolar resorption 
may be induced by the continuation of the changed position. An inter- 
val of two days usually suffices for the pericementum to recover from 
the disturbance, when the restorative procedures may be conducted. 

The retention of the space may be effected with gutta-percha or with 
the plastic cements, — the first being suitable when an open cavity 
appears ; zinc phosphate when from the smallness of the cavity gutta- 



188 PRELIMINARY PREPARATION OF THE TEETH. 

percha may not be readily retained. Oxychlorid of zinc should be used 
when the cavities are shallow but sensitive, — the reason for which 
will appear later. It is generally advisable to introduce a thin wedge 
of wood at the cervix and in contact with the gum to prevent the re- 
taining material from impinging upon this tissue and to give a base to 
support the introducing force. 

Exposure of Cervical Margins. — When cavities extend beneath 
the gum, which frequently is the case when caries has recurred above 
the cervical margins of fillings, it becomes necessary to force the gum 
somewhat above the carious border. This should be done quickly 
rather than slowly, otherwise in adult subjects the continued pressure 
may arouse diffused inflammatory disturbance of the contiguous tissues. 
Generally it is preferable first to cut away the gum between the teeth 
with a straight, narrow bistoury, and gently force red gutta-percha 
against the gum, gradually moulding it to the form of the depression. 
Cotton pellets for this purpose are not admissible unless they are anti- 
septically charged, for which purpose an admixture of aristol with the 
cotton is the most suitable, since not being soluble in water it better 
maintains the asepsis. Cotton may be conveniently charged with aris- 
tol by saturating it with a solution of aristol in chloroform and allow- 
ing the greater portion of the solvent to evaporate before introducing 
the pledget. 

When hypersensitiveness of the gum tissues exists it is admissible to 
paralyze the sensation with a suitable solution of cocain, previous to 
introducing the pellet of either gutta-percha or cotton fiber. A four 
per cent, solution of cocain hydrochlorid applied upon cotton to the 
sensitive tissues will speedily relieve the condition. 



CHAPTER VII. 

PRELIMINARY PREPARATION OF CAVITIES — TREATMENT 
OF HYPERSENSITIVE DENTIN BY SEDATIVES, OBTUND- 
ENTS, LOCAL AND GENERAL ANESTHETICS— STERILIZA- 
TION, WITH A BRIEF CONSIDERATION OF THE PHYSIO- 
LOGICAL AND THERAPEUTIC ACTION OF THE MEDICA- 
MENTS USED. 

By Louis Jack, D. D. S. 



Hypersensitive Dentin. 

Dentinal hypersensitiveness frequently presents the most serious 
impediment to the procedures connected with the treatment of dental 
caries. This condition must be considered an exaltation of the normal 
sensitiveness of the dentin, and presents a wide range from slight pain 
on contact being made to so high a degree of sensitiveness as to be un- 
endurable. In the latter instance persons of the greatest capacity for 
tolerating pain will shrink from the most careful instrumentation. Im- 
mediately upon the opening of a carious cavity there usually are indica- 
tions of excitement of the vital elements of the dentin. This con- 
dition may be so slight as to present no obstacle to further procedures, 
or it may on the other hand be so excessive as to forbid all instru- 
mentation until a reduction of the sensitiveness has been effected. 

This altered state of the dentin has been considered by some as one 
of inflammation of the dentin. As the opportunity does not exist for 
the usual concomitants of inflammation as pathologically defined and 
which are induced by the alterations of the circulation of the blood, 
viz. heat, redness and swelling, with exaltation of nervous function 
caused by the additional supply of arterial blood, the term inflamma- 
tion is a questionable one to apply to a hyperesthetic condition of 
dentin. This manifestation is more logically explainable as a disturb- 
ance caused by changed relations of a tissue which is naturally pro- 
tected by the enamel from irritating influences. The relation of the 
enamel and the dentin is analogous to that of the epidermal coat of 
the skin and the rete mucosum. Pain caused by abrasion of the 
epidermis is immediate and acute, and occurs before the increased 
supply of blood increases the intensity of it. It is hence induced by 

189 



190 PRELIMINARY PREPARATION 

the altered relation of the mucosum. The analogy is further borne out 
by the fact that in each instance a protective covering affords salu- 
tary relief. 

The normal sensitivity of dentin is not high, as is shown by an 
immediate examination of a surface exposed by accident, but after a 
few days the denuded surface manifests impatience of mechanical 
contact and of applications of cold, which proves that the altered rela- 
tions induce a condition of the part similar to the condition of the 
skin when the epidermis is broken. This appears to be the case in- 
dependent of the influence of chemical agencies, as exaltation of sensi- 
tiveness occurs when the fluids of the mouth are in a normal state. 
The same indications are presented when a non-sensitive cavity is pre- 
pared, as here, in case the cavity be not protected by a stopping, the 
same phenomenon subsequently appears. 

Generally also, in such cases, if a stopping is inserted without pre- 
viously effecting a coagulation of the surface of the cavity, pain arises 
upon reduction of temperature. This condition is designated as sec- 
ondary sensitivity, which is caused by the traumatism. In some cases 
of this kind the pain becomes so great as to require the removal of the 
stopping and the carbolization of the cavity. In extreme cases reflected 
pain in the other teeth may appear in consequence of the disturbed 
relations making an impression upon the nervous elements of the pulp. 

When exposure of the dentin has been brought about by caries, the 
sensitivity excited is liable to be much exalted above the normal, and is 
only prevented from giving constant indications of this condition by 
the presence of the carious matter, which, being a poor conductor of 
heat, in a measure protects the pulp from thermal irritation. This 
accounts for the fact that while there may sometimes be acute pain in 
the early stages of decay of dentin, the irritability and reaction of the 
pulp appear to become less as the caries advances. 

When the teeth are undergoing rapid decay the dentin is more sen- 
sitive than when the carious process is slow. As the color of the 
carious matter gives some indication of the rate of progress, we may 
from this indication form an impression of the probable degree of 
sensitiveness. When the carious matter is light, the action has been 
rapid ; when it is yellow or light brown it is less active ; and when it 
is dark brown or black, it has progressed very slowly. In some cases 
of the last character, when the parts are subject to friction, spontaneous 
cessation of decay takes place. The parts are then nearly devoid of 
sensitiveness. The process by which the dentinal tubuli become oblit- 
erated by calcific deposits is called ebumation. When the dentin be- 
comes exposed by attrition, that tissue is not as greatly irritated as it is 
by the progress of caries, since by reason of the gradual loss of sub- 



HYPERSENSITIVE DENTIN. 191 

stance changes take place within the tubules by which their capacity to 
convey sensation is diminished or obliterated as the case may be. 

Wlien the gum recedes, exposing the ceruentum, a very high degree of 
sensitivity is often excited, which is prone to decline by spontaneous 
changes of structure. There is often here the added influence of acid 
conditions of the mucous secretions where they flow out upon the teeth 
at this point, and where, too, the parts are not easily cleansed. It is a 
notable fact in connection with cervical hypersensitiveness that while it 
persists these parts are less liable to decay than when loss of sensitive- 
ness here takes place. 

The area of hypersensitivity usually is not evenly distributed 
throughout the carious cavity, but has its chief seat near the line of 
union of the dentin with the enamel, thus bearing out the law T that 
sensitivity is greatest at the terminal end-organs of the sensory nerves, 
with the further qualification that the more minute the fibrillar the 
greater may be the acuteness of the sensitivity. This fact is illus- 
trated by the example of cavities in the occlusal surfaces of the molars, 
which manifest pain only at the margins ; is only less evident in the 
cavities of approximal surfaces, and is strongly shown in the shallow 
buccal and labial cavities, wdiich present their w T hole surfaces near the 
line of juncture of enamel and dentin. 

In most cases of caries, the zone of highest sensitivity is immediately 
beneath the soft portion of the decay, and when this layer of dentin is 
cut away the pain becomes less, in some instances approaching the nor- 
mal. This statement, however, has force only in the milder manifesta- 
tions of this condition. 

The Effect of Acid Conditions of the Oral Fluids. — In the pre- 
vious chapter some allusion was made to the fact that an acid state of 
the oral fluids is detrimental to the teeth as promoting carious action, 
and that alkaline or even neutral states have a retarding influence. 
Here it must be considered as an axiom that no cause is so active as a 
primary influence in inducing excessive dentinal sensitivity as a con- 
stant slightly acid state of these fluids ; and, conversely, that a neutral 
or slightly alkaline state is non-irritating. These conditions should be 
kept in constant view in dealing with this subject. 

The degree of sensitivity of dentin is modified by a variety of 
other general conditions. These are — relative density of the structure, 
rapidity of the carious action, and the constitutional peculiarities of the 
person which are connected most directly with nervous impressiona- 
bility to disturbances of the tissues. 

The rate of progress of caries exerts considerable modifying influence 
over dentinal sensitivity. When caries is of slow progress the amount 
of organic tissue exposed to irritation is comparatively small, for the 



192 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

reason that the well-known salutary and protective changes of structure 
go on coincidently with the slow inroad. The slight irritation of slowly 
advancing caries to some extent exerts a stimulating influence toward 
inducing tubular deposits. On the other hand, when the carious pro- 
cess progresses with rapidity, reparative efforts upon the part of the 
pulp are paralyzed, the organic elements of the tissue become denuded 
to a greater extent, and therefore sensitivity is increased to a propor- 
tionate degree. 

As these fibrillar elements are the means of extending the irritation 
to the pulp of which they are the peripheral prolongations, it is evident 
how important a factor the active advance of caries is, and also to what 
extent the rapidity of the process increases the morbid concomitants 
of dental caries. It has been pointed out that the area of hypersensi- 
tiveness generally pertains to a narrow line at the outer limit of the 
dentin, but in rapid caries this line is a broader one. 

The anatomical element of the dentin concerned with its sensi- 
tivity is contained within the tubuli. While the exact nature of the 
matter in these tubules has not yet been certainly determined, it has 
been shown to have sufficient consistence to permit of extension, as 
in separating sections under the microscope what appear to be fibers 
have been seen. Also the same appearance has been presented in fresh 
specimens when the pulp has been drawn away from the dentin. It 
is not difficult in reviewing these facts in connection with the various 
conditions and phases of dentinal sensitivity to conclude that the exalta- 
tion is inseparably connected with an irritated state of the tubular con- 
tents. The variation in the degree of sensitivity of different teeth of 
the same mouth — of those which are side by side and in a similar 
' degree of progress of carious action ; the profound fact, heretofore stated, 
that the dentin at a short distance beneath the decay is much less sen- 
sitive ; that in some instances sedatives modify the degree of pain, and 
that coagulants produce a marked impression upon the capacity of the 
tubular contents to convey sensation, force by inference the conclusion 
that in diseased conditions this anatomical element is largely concerned 
in conveying impressions to the central organ of the tooth. 

It is also undoubted that unusually high sensitivity of dentin is an 
inherent constitutional condition with some persons, and that it pertains 
to some families apparently as an inheritance, but may be explained in 
these instances as the transmission of acute nervous impressionability. 

In connection with this subject should be considered the further 
observation that the temperature sense of the teeth is various ; that with 
some the application of ice makes no impression upon the teeth when 
in normal condition, while with others in the same condition the least 
cold induces pain. It would further appear that the degree of sensitivity 



TREATMENT OF DENTINAL HYPERSENSITIVITY. 193 

when caries occurs bears some relation to the relative tolerance of the 
teeth to reduction of temperature. 

On these premises it is not difficult to account for the manifestation 
of acute sensitivity, and to build thereon an hypothesis governing the 
various conditions presented by dentin when it is subjected to the irri- 
tation of the carious process. These views have steadily gained sup- 
port with the advance of microscopic study of the tissues, and have 
supplanted the older view that the sensitivity of dentin is a result of 
mechanical vibrations extending to the dental pulp. 

Treatment op Hypersensitivity of the Dentin. 

Having considered the general principles governing hypersensitivity 
of dentin, we are prepared to enter upon a study of the treatment. 
This is to be considered under the following general lines : namely, 
the therapeutic, the chemical, the anesthetic, and the mechanical. 

Treatment of Slight Hypersensitivity. — The first requisites to be 
observed here are a calm manner and earnest sympathy, accompanied 
with the assurance that if severity of pain occurs, mitigating means will 
be resorted to. It is an important and laudable object to remove dread 
and secure confidence, which is attained among other means by select- 
ing at first the simpler and less painful operations. When confidence 
is secured, slight pain arouses the courage of the patient. The effect of 
the opposite course of indifference and harsh cutting alarms the patient, 
arouses apprehension, and greatly increases the nervous exaltation. 

In the simpler cases sharp instruments used with quick, light, and 
rapid movements are called for. It should in this connection be noted 
that cutting in this manner stimulates somewhat the nervous force of 
the patient, and if the movements are in very quick succession they 
appear to paralyze the part ; the pain is thus lessened in comparison 
with deliberate and slow instrumentation. The movements of the ex- 
cavators should be in a direction away from the pulp rather than toward 
it, and the cuts should be by drawing the points instead of pushing 
them ; this is for the reason that the pressure in the latter case is greater 
than in the former. 

"When the sensitiveness is so great as to interdict immediate excava- 
tion and formation of the cavity, some method of treatment of the sur- 
face is required to overcome or to confine it within a tolerable degree. 

The Therapeutic Treatment. — Under this head the available reme- 
dies are morphin, veratrin, and eocain, — each of them being applied 
with glycerin as a menstruum. It should be stated that neither have 
much immediate effect, and therefore they should be sealed in the cavity 
after the opening in the enamel has been prepared, and the softer caries 
has been lifted and peeled off. The closure should be effected by 

13 



194 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

means of gutta-percha, or with what is probably better, a thin paste of 
phosphate of zinc laid over the dressing. After some days the pain will 
be found diminished in many instances. The therapeusis is effected by 
the absorption of these sedatives by the partially disorganized tissues. 
Another method of applying cocain is to secure the cavity from the 
entrance of moisture, and after desiccating the surface a saturated 
pledget of vapocain, a solution of cocain in sulfuric ether, is introduced. 
As evaporation of the ether takes place cocain is forced by osmosis into 
the tissue. In cases of subacute sensitivity this means frequently is 
efficacious, but is of little value in hypersensitive conditions. It is 
advantageous as preparatory to this line of treatment first to neutralize 
the acidity of the cavity with an alkaline solution, which may be either 
ammonia, sodium carbonate, or sodium dioxid, afterward removing the 
excess of alkali by thorough washing with warm water. 



Treatment op Hypersensitivity of Dentin by Electrical 

Osmosis. 

Within a recent period a means of treatment of this condition has 
become prevalent which has been designated by the terms cata- 
phoresis, electrical diffusion, and electrical osmosis. It 
has been demonstrated that the action of electrical currents conveys 
fluids, with the substances held in solution, from the positive elec- 
trode toward the negative electrode. Further, that an electrical 
current passing through a membrane accelerates the natural process 
of osmotic diffusion if the positive pole is applied on the side of a 
membrane or tissue from which the osmotic diffusion is taking place ; 
in case the situation of the poles be reversed, the osmosis is retarded or 
prevented from occurrence or is reversed. This action bears some 
analogy to that which takes place in electro-metallurgy when a metal 
in solution is conveyed from the anode (positive pole), and is deposited 
upon the cathode (negative pole). If the current be reversed the 
deposited metal is again taken up by the solution and is conveyed 
back again to the other pole. This is a law connected with the 
passage of electrical currents through fluids which are capable of con- 
duction. 

The following will illustrate the action which takes place : " If two 
compartments separated by a membrane are filled with a fluid and in 
each an electrode is placed, there is a streaming of the fluid through the 
septum from the positive to the negative pole, so that in time there is 
an increase in the negative side. This osmotic action, as is well known, 
occurs naturally between two fluids of unequal density from the lighter 
to the denser liquid, but if the anode is placed in the denser liquid 



DENTINAL ANESTHESIA BY ELECTRICAL OSMOSIS. 195 

and the cathode in the lighter the natural osmotic current is not only 
overcome but is reversed." 

If a substance containing water, as a ball of wet clay or a piece of 
muscular tissue, have an anode connected with a current of sufficiently 
high potential attached to one side, with a cathode attached to the oppo- 
site side, the watery contents of the substance are conveyed to and appear 
in excess on the cathodal side ; at the same time the anodal side be- 
comes less damp ; also, if a capillary tube be filled with water and an 
anode and a cathode be similarly arranged, the water flows toward the 
cathode. 

As a membrane or tissue may be considered to be a series of tubes 
in close contiguity, it is apparent that the movement of fluids must take 
place through them in the direction the current is passing. 

These examples are an expression of electrical force. The applica- 
tion of this law of the passage of fluids from a higher to a lower elec- 
trical potential is the fundamental process which is employed in electrical 
diffusion of medicaments. The depth to which medicaments may be 
conveyed depends upon the conductivity of the tissue and that of the 
medicament which is being applied. 

" The cataphoric action of electricity has often been made use of 
experimentally to introduce drugs into the system through the skin. 
In man quinin and potassium iodid have been thus introduced and 
subsequently been detected in the urine." 

As early as 1859 Dr. B. W. Richardson used this process to pro- 
duce local anesthesia, and completely demonstrated its power in this 
direction. It has also been clearly proven that when a solution of 
cocain is applied to the skin, its characteristic action upon the mucous 
membrane will not here take place. But when the anode is wet with 
the solution and a galvanic current is passed through the epidermis 
to the cathode, placed upon an indifferent surface, anesthesia is effected 
over the surface covered by the anode and to an indefinite distance 
inward. 

This effect is not produced by the current alone, which has been 
abundantly proved by conclusive experiments, these having been fol- 
lowed by demonstrations confirming the above statement. When the 
medicaments so applied have anesthetic or analgesic properties their 
characteristic effects are produced. 

When this principle is applied to the transfer of medicaments it is 
found that they pass for an indefinite distance into the contiguous tissue 
along with the current from the anode toward the cathode, but with 
some degree of diffusion ; the diffusion depending upon the resistance 
of the tissue and upon the extent of the surface of the cathodal (nega- 
tive) electrode. 



196 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

GENERAL PRINCIPLES INVOLVED IN THE METHOD. 

The application of electricity requires the consideration of the 
general principles or laws governing its transmission. 

The source of this force is to be found in chemical transformation. 
Under the laws of the correlation of force it is capable of being con- 
verted into heat, light, magnetism, and mechanical power, and may be 
used to disorganize substances, when its action is called electrolysis. Its 
movements are constant in their direction, viz. from bodies of high to 
those of low potentiality. 

In perfectly conducting substances electricity moves with entire free- 
dom under any electro-motive force however small. 

In perfectly non-conducting substances electricity will not move 
under any electro-motive force however great. 

In imperfectly conducting substances electricity moves only on the 
exhibition of intense electro-motive force, the force varying according 
as the substance is a more or less indifferent conductor. 

Electricity has two elemental properties. These are defined as cur- 
rent strength, designated by the term amperage; and electro-motive 
force, which is termed its voltage. 

The active energy of electricity depends upon the first property, 
its distribution upon the latter. Since it must be assumed that few 
bodies are perfect conductors, this force or pressure is of that degree 
which may be required in any given case to move the active energy, 
the amperage, against the resistance it meets with. 
The unit of strength is the ampere. 
The unit of pressure is the volt. 
The unit of resistance is the ohm. 
The unit of power is the watt. 

A volt represents the electro-motive force (E. M. F.) required to 
impel one ampere of current through one ohm of resistance. 

An ampere of current is so much as will deposit 0.00118 gram of 
silver per second when passing through a standard solution of nitrate 
of silver — or which will decompose 0.09326 milligram of water in one 
second. Hence the ampere is the measure of rate of flow of an electri- 
cal current, and in connection with the voltage measures the energy of 
the current. 

The unit of resistance (ohm) is that degree of resistance which 
will permit the passage of one ampere of current at one volt of 
pressure. 

The watt is the power exerted by one ampere of current at one volt 
of pressure. 

In the economic application of electricity its transmission is effected 



DENTINAL ANESTHESIA BY ELECTRICAL OSMOSIS. 197 

through metallic conductors. The resistance of these is varied by the 
character of the metal, the cross section, and the distance. For certain 
purposes other substances are employed to effect greater resistance than 
the metals. 

The current strength flowing in a circuit is equal to the pressure 
divided by the resistance. 

The resistance equals the pressure divided by the strength. 

The pressure equals the strength multiplied by the resistance. In 
elementary terms : 

Amperes = volts -s- ohms. 

Ohms = volts -s- amperes. 

Volts = amperes X ohms. 

Watts = volts X amperes. 

It follows from the formula that the amount of power and the cost 
of producing it is the same whether the current is of large amperage at 
low voltage or of small amperage at high voltage. Thus an incandes- 
cent lamp may be supplied by 100 volts at J ampere or by 50 volts at 

1 ampere — the result in each case being 50 watts. 

Comparative Illustration. — Given a current of 100 volts at fifteen 
amperes, and we wish to use only \ ampere, the resistance to be put 
in the circuit is found thus : 100 v -^2^a = 40 o. 

In case we have 2-| amperes under 7 ohms resistance, it requires 
17 }j volts to move this degree of amperage through the given resistance, 
thus : 2J a X 7 r = 17-J- v. If one has a current of 110 volts, and de- 
sires to use a J-horse-power motor, the least amperage required is 1 t % 9 q-, 
which is found by dividing 186 watts by 110. These examples make 
plain the means of determining the character of current required for 
any given purpose. 

Electrical force may be produced from its source in galvanic cells by 
arranging them in series or in multiple. If in series the voltage is 
the sum of the volts of the cells so arranged, and the amperage is that 
of each of the cells. If joined in multiple, the strength in amperes 
is the sum of the amperes of the cells, and the voltage is that of one 
cell. 

Fig. 152 l represents the arranging of cells in series, the positive of 
one with the negative of the next. In case each cell has a voltage of 

2 and an amperage of 1 the electro-motive force of 5 cells will be 10 
volts at 1 ampere. 

Fig. 153 2 represents the joining of cells in multiple. Here all the 
x See Dental Cosmos, December 1896, p. 998. 2 Ibid. 



198 



PRELIMINARY PREPARATION OF CAVITIES, ETC. 



positive elements are joined together and similarly all the negative to 
each other. The voltage now is 2 and the amperage 5. 



Fig. 152. 



+ 



m 



The former method of assembling the cells is designated as "high 
tension/' the latter method as "low tension." When the source is the 




dynamo, high and low tension are produced by the strength or weakness 
of the magnetic field, 

For electrical osmosis the source should be from batteries in series, 
for the reason that in multiple the amperage would be too great when 
the voltage is of sufficient force to overcome the resistance. 

The degree of electrical energy tolerated by living dentin is exceed- 
ingly small, on account of the peculiar and intense pain excited by the 
transmission of electrical currents through the teeth. This is shown by 
the low initial voltage of the batteries used for the purpose, varying 
from less than 5 to rarely more than 20. But the initial passage of a 
current of as high electro-motive force as these would not be tolerable, 
and must therefore be reduced by suitable methods of effecting re- 
sistance. 

The apparatus used for this purpose is the controller, the purpose of 
which is through its resistance to diminish the energy of the current to 
sufficient weakness to meet the requirements of any given case. All 
forms are constructed on the principle of the use of materials which are 
highly resistant of the passage of electric currents. These substances 



DENTINAL ANESTHESIA BY ELECTRICAL OSMOSIS. 199 

are water, carbon, graphite, and coils of wire of known high resistance, 
the most effective being of German silver. In the case of the latter the 
degree of resistance is regulated by the length and fineness of the wire, 
the cross section being reduced to the size which will conduct the cur- 
rent without excessive heating, and to that end it is graded with refer- 
ence to the initial amperage of the current. In comparison with silver 
as a unit German silver has a resistance of 13.92. 

The carbon and graphite controllers usually are constructed in the 
form of a broken ring — one pole of the battery being connected at one 
end of the ring, the other pole being attached to an index which travels 
over this annular disk. This method of construction gives a fine grada- 
tion of current with high resistance. It may be used in connection with a 
German-silver wire rheostat, where currents of great strength are used 
for reasons which will appear later. In the use of high-voltage cur- 
rents, such as the 110-volt circuit, it may be switched through the 
coils to a nearly definite low voltage by means of a rheostat, when 
the adaptation to the case may be effected through the graphite con- 
troller. 

In the arrangement of the apparatus to effect electrical osmosis the 
battery, the controller, the instruments of observation, and the patient 
are in series. In the analysis of the course of the current it appears that 
the patient is another element of resistance, and that dentin is more 
highly resistant than the other tissues. In other words, there are two 
resistances in the circuit — the controller and the tissues of the patient. 
The result of the resistance of the dentin, unless the initial voltage is 
small and is reduced by the controller to an infinitesimal degree, is the 
occurrence of pain, which takes place with different persons at various 
degrees of amperage. The approach to intolerance of the current is 
designated the " pain limit." This condition has been assumed by some 
observers to be caused by the evolution of heat in the dentin con- 
sequent upon the resistance of this tissue. This view is not now con- 
sidered to be conclusive, as the calculated elevation of temperature at 
■^q milliampere is not sufficient to account for the degree of irritation 
which occurs on increasing the rate of flow. This determination 
leaves two other hypotheses to account for the irritation : a, the ten- 
dency of the current to disorganize some of the anatomical elements of 
the canaliculi ; and 6, the osmotic pressure of the migration of the 
medicaments. Here the student is not confused with consideration of 
the complicated forces which are in action connected with the electroly- 
sis of the cocain solution. 1 

The pain limit is variable with different persons, and in different 

1 See "The Foundation Principles of Dental Cataphoresis" Items of Interest, vol. xx. 
p. 345 et seq. 



200 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

teeth of the same person. With some it is reached with the first 
influx of the current at low voltage with a record of ■£$ milliampere, 
this low record indicating high resistance of dentin and permitting but- 
slow increase of the force until after cocain has diminished the sensitiv- 
ity of the irritated surface. With others the pain limit may not be 
reached with a voltage of 20 and a recorded amperage of T 3 ¥ to -^ milli- 
ampere. In respect of electrical irritation there must be taken into 
account also the high nervous sensitivity of some persons, as with these 
there usually appears greater susceptibility to electrical irritation. 

The following table of calculated resistances shows the resistance 
in ohms, and the liability to the generation of heat in the dental tissues 
in view of their density, or the tendency to disorganization as previously 
stated, and it suggests that care be used in the application of electrical 
force for the purpose under consideration. 

With 15 volts initial pressure at t 4 q milliampere in circuit the ohms are 37,500. 



15 

10 

10 

5 

5 



150,000. 

25,000. 
100,000. 

12,500. 

50,000. 



As the resistance of the body including the dental tissues varies from 
10,000 to almost 70,000 ohms, it would appear necessary that the con- 
troller should have at the highest point a resistance of not less than 
400,000 ohms. This degree of resistance is required to obviate the 
effect of impulse which may occur in closing the circuit. Occasionally 
slight shock is felt at 600,000 ohms. 

The varying resistance of the current through the tissues depends 
upon the density of the dentin, the distance traversed, the condition 
of the surface of the skin, and the thickness of the adipose tissues. 

The average resistance of the patient as recorded by Dr. W. A. Price 
is about 25,000 ohms from cavity to hand, and the difference of resistance 
from tooth to hand and cheek to hand is from 3000 to 5000 ohms. He 
reports one case where the resistance from cavity to hand with a 40 per 
cent, solution of cocain was 28,500 ohms, which on placing the pad on 
the cheek was reduced to 23,000 ohms. 

Dr. Price further places the average resistance from hand to tongue 
at 9000 ohms, and from cheek to tongue at from 3000 to 7000. This 
would make the resistance of the dentin nearly 20,000 ohms. An 
exact determination of the resistance of the skin in any given case 
would enable a very close approximation for the dentin to be calculated. 

The condition of the cavity as to relative moisture and the degree 
of saturation of the pledget of cotton containing the anesthetizing agent 



DENTINAL ANESTHESIA BY ELECTRICAL OSMOSIS. 201 

as well as the percentage of the medicament exert a considerable quali- 
fying control of the resistance, as appears from the experiments of 
Dr. Price. When a section of dentin partially dry on the surface had 
a resistance of 30,000 ohms, after being dried and saturated with a 40 
per cent, solution of cocain the resistance was reduced to 4500 ohms. 

The principles here stated and the facts presented apparently demon- 
strate the importance of careful selection of the degree of voltage at 
the battery ; of the use of a relatively low amperage to the voltage ; 
of the necessity of controlling the current within the boundary of the 
pain limit ; of the importance of avoiding impulses of current by rapid 
advancement or by movements of or displacements of the anode ; and 
of attention to the maintenance of a constantly moist state of the anodal 
and cathodal contacts. 

These principles and facts have led to the application of galvanic 
currents for the production of a state of anesthesia of hypersensitive 
dentin ; and the results of experimentation in this direction have proven 
that the same effects have followed here as have occurred in the softer 
tissues. 

The extreme sensitiveness of the teeth to electrical currents and their 
resistance to the passage of electrical force were obstacles to the earlier 
application of this method of treatment in dentistry. The absence of 
means to control the current strength (the amperage) and to reduce the 
pressure (the voltage) to the capacity of the teeth prevented experi- 
mentation in this direction until within a comparatively recent period. 

The current strength that is tolerable at the commencement of the 
application is so small as to be scarcely measurable in many instances. 
To produce this small current, either the battery voltage must be low 
or the resistance in the controller exceedingly high. 

Any form of battery which is constant when the amperage of the 
individual cell is from one-fourth to one-half of an ampere will have 
sufficient current strength. The E. M. F. may be from one to two 
volts per cell. 

The voltage required to produce the necessary electro-motive force in 
an application to the teeth to produce dentinal anesthesia varies from 
five to thirty. For children and where the teeth are apparently not 
dense, ten cells sometimes are sufficient, but generally fifteen to twenty 
are needed. The cells should be arranged in series and connected in a 
manner which enables the selection of any number to produce the re- 
quired E. M. F. for any given case and to permit an increase of cells 
during the administration. 

The most important condition of the electrical force for the purpose 
is that the amperage shall be inconsiderable, since high amperage is intol- 
erable to the teeth. As the most efficient results are produced when the 



202 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

recorded amperage is not over three-tenths of a milliampere, the use of a 
current of high amperage is unnecessary, and it is attended with distress. 
High voltage is equally painful, as the endeavor to force the current 
against the resistance of the dentin results in electrical irritation, as 
already described. 

The chlorid of silver cell is probably the one best suited for the 
purpose, as its electro-motive force remains practically constant under 
various conditions. The E. M. F. of each cell is about one volt ; the 
internal resistance eight ohms ; the strength one-fifth of an ampere. 
This battery on account of its constancy and durability is largely used 
in electro-medical apparatus. It is now furnished dry, and is more 
acceptable as being less troublesome on this account. 

The dry Leclanche battery is also one of the best forms, as it is an 
open-circuit battery. As long as the circuit is open there is no action 
in the cell and consequently there is no loss. 

At present these two forms of galvanic battery cell appear to be the 
kinds best adapted for the purpose of inducing electrical osmosis. 

The storage battery may also be used with advantage, but the plates 
should be small ; each cell should contain but three plates to give the 
proper degree of current strength. When the plates are 3x3 inches 
the normal amperage at eight hours' discharge is five-eighths of an 
ampere. The voltage of each cell is two. This when discharged under 
the resistance required for application to sensitive dentin in cataphoric 
work should have a capacity for 800 applications, providing waste of 
current strength does not occur from accidental short-circuiting. 

The life of a chlorid of silver dry cell battery is stated to be 700 
hours of cataphoric work under a high resistance of tissue, but it must 
be remembered that the continuance of energy of all forms of battery is 
varied by the resistance and the conversion of electrical energy into heat 
by the controller which regulates the amperage and the voltage. This 
principle applies to all sources of electrical force. 

The controller which at present appears best adapted to be interposed 
between the battery and the anode is the Willms controller, which, as 
before stated, should be constructed with a resistance at the highest 
point of at least 400,000 ohms. The gradations of resistance decrease 
from this through 112 contact points. These permit a very gradual 
reduction of the resistance as the switch is conveyed from point to 
point in the circle. This controller also has the advantage of being 
moderate in cost and easily procurable. 

An important adjunct of any apparatus is a reliable milliampdremeter. 
This should have a scale to record divisions of fortieths of a milliampere, 
from the fact that the amperage of the current through the dentin is fre- 
quently efficient at less than two-tenths of a milliampere. The milli- 



DENTINAL ANESTHESIA BY ELECTRICAL OSMOSIS. 203 

amperemeter also aids in detecting leakage of current, as where the 
indicated amperage exceeds five-tenths milliampere there is reason to 
suspect imperfection of the insulation of the tooth. In this case a 
longer period than usual will be required to effect the anesthetization, 
and the degree of this effect may be less. 

The use of the direct current generated by the dynamo is of ques- 
tionable utility as compared with the current from a battery. The 
current from the dynamo is subject to changes of voltage and the 
amperage is liable to fluctuations consequent upon alterations of the 
load in the general circuit. This instability causes a series of pulsat- 
ing shocks upon sensitive dentin and the pulp, which react with the 
expression of pain. The possibility of the transmission of severe 
shock through accidental grounding or defective apparatus where such 
excessive voltage is used is another and sufficient reason why the 
steady and low-voltage current of a battery is preferable for this class 
of operations. 

TECHNIQUE OF THE ADMINISTRATION. 

At the present period cocain has been found to be the most effective 
anesthetic for obtunding dentinal sensitivity by electrical osmosis. It 
is used in strength varying from 12 to 24 per cent., and by some as 
high as 40 per cent, has been used ; 1^ grain of one of the salts of 
cocain added to 5 minims of water procures a solution of 24 per cent. ; 
to 1\ minims, 18 per cent. ; to 10 minims, 12 per cent. 

The salts of cocain which have been used are the hydrochlorid and 
the citrate. Each is efficient in the strength stated. The resistance of 
cocain citrate is for 12 percent, solution 234 ohms; for 24 percent. 
153 ohms. The resistance of cocain hydrochlorid is for 12 per cent, 
solution 80.85; for 24 per cent, 61.25. These provings indicate that 
the hydrochlorid is the better salt of cocain for the purpose. 1 

The tooth to be operated upon is isolated by means of a rubber dam 
and is ligated at the cervix to prevent leakage of current, If there are 
metallic fillings in the tooth, these should be covered with a coat of 
varnish carefully laid on and dried. This precaution does not always 
possess the value claimed for it, as the dentin beneath a metal filling, 
because of its density or lack of porosity, will not convey the current 
as well as the carious matter and the softer dentin of the fresh cavity. 
In some cavities where caries has occurred at the cervix above gold 
fillings, and which do not permit of complete isolation of the fillings, 
the cataphoric influence is not interfered with. 

The carious matter should not be completely removed and need only 
be partially dried. The cavity is loosely filled with a small pledget 

x The writer is indebted for the determination of these resistances of cocain solutions, 
etc., to Mr. A. W. Schramm, of the University of Pennsylvania. 



204 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

of lint saturated with the solution of cocain. The anode, the point of 
which is of platinum, is covered with a thin stratum of lint which is 
dipped in the solution and inserted in the cavity in contact with the 
pledget previously introduced. The cathode, which should be at least 
one and a half inches in diameter, is placed at a convenient place on 
the face or neck. The desired number of cells are placed in circuit 
with the controller at zero. 

All being ready, the switch is placed on the first contact point. At 
this moment, however great the resistance of the controller, a slight 
sensation is sometimes experienced, but at once the switch may be 
passed slowly over the contacts until some sign from the patient indi- 
cates that the current is being felt. Here it is retained until subsidence 
of the sensation occurs, when the resistance of the controller should 
be very gradually lessened. This process is continued, keeping con- 
stantly within the limit of pain ; at length the switch may be more 
rapidly advanced. When this can be done without thrill, the indication 
is that anesthesia is complete. The switch is then carried back to the 
zero point, when the excavation may be conducted. 

Where it is necessary to remove the rubber (as the solution of cocain 
is strong) the preparation should be previously washed away to prevent 
any of it from being swallowed. 

The period of administration varies from eight to fifteen minutes 
in ordinary cases where the indicated amperage is from t 1 q to T 2 ^ milli- 
ampere. When, however, the dentin is dense, as where denudation has 
taken place by attrition, a longer time is required to effect penetration 
by the cocain. Also where from any condition the indicated amperage 
at first is -^V milliampere or less, time and patience are demanded. 
The loss of time is more apparent than real, since there usually is a 
direct relation between the pain limit at very low amperage and high 
sensitivity ; what is apparently lost in the time of the application is 
gained in the after facility of instrumentation. 

The sphere of the action extends throughout the cavity, but to a 
somewhat less degree at the extreme lateral margins, and more particu- 
larly at the occlusal margin. Here usually no more than a normal 
degree of sensitivity is found, which appears to be due to the fact that 
in making the retentive undercutting this procedure may extend beyond 
the sphere of the complete influence of the cocain. The effect is most 
pronounced when the application is made directly to the carious matter. 
In this case the diffusion is greater than when the caries is freely re- 
moved, for the reason that in the latter case the current seeks the line of 
least resistance toward the pulp. It follows from this that when all 
parts of the cavity are equidistant from the pulp, the action should be 
more effective throughout upon the surface of the dentin. This is 



DENTINAL ANESTHESIA BY ELECTRICAL OSMOSIS. 205 

proven to be the case from the profound effect in cavities upon buccal 
and labial surfaces and in shallow cavities of occlusal surfaces. Besides 
the less diffusion of the cocain when the carious matter is removed, 
a degree of electrical force which in the former case is easily tolerated 
becomes painful. These facts make conclusive the importance of retain- 
ing some of the carious contents of the cavity. 

An explanation of the influence of the current is found in the prin- 
ciples and examples given on page 194. As the anode is put in con- 
nection with the lint saturated with the cocain solution the fluids of the 
tooth advance toward the pulp through the canaliculi, their place being 
taken by the solution of cocain. At the same time it is observed 
that loss of fluid from the lint occurs, necessitating additions to 
maintain the proper wetness, some loss of water taking place by 
evaporation. 

Conditions Influencing Tolerance of the Current. — As already stated, 
when the electrical force is brought into connection with the carious 
matter the irritation caused by the current is of trifling degree and 
soon subsides, indicating that the anesthetic effect has been produced ; 
but when the cavity is denuded of caries the above-stated degree of 
current force is not so tolerable, the irritation continues longer and 
does not subside in the same manner, but the effect upon the tissue is 
nearly if not quite as marked. The nearer the bottom of the cavity 
is to the pulp, the greater the irritation. Hence in this condition it 
becomes necessary to begin with a low degree of voltage. While in 
the one case fifteen cells may be selected, in the other ten cells are 
more satisfactory. 

To avoid the removal of caries the condition of the dentin as regards 
sensitivity should be tested at the line of its connection with the 
enamel. 

Some stress has been laid upon the necessity for rendering the solu- 
tion of cocain more highly conductive. This claim is probably more 
theoretical than practical in its character, since experience with the 
solutions given indicates that the conductivity is sufficient, and that the 
resistance is more to be looked for in the dentin than in the solution, 
and that when the tooth has become tolerant of the current at a com- 
paratively low voltage an increase of pressure of the current is suf- 
ficient to complete the anesthesia. 

The form of the platixum axode should be such as to permit its 
easy entrance into the cavity when its point is covered with a layer of 
absorbent lint. For all cavities in the approxitnal surfaces and in most 
occlusal positions an excellent form of anode is made by curling the 
end of a fine platinum wire (No. 25) into a flat knot, or forming it in a 
loop. On the loop a properly sized piece of lint may be gathered. 



206 



PRELIMINARY PREPARATION OF CAVITIES, ETC. 



This may be packed into the cavity and secured with additional lint 
when required. This method is a self-sustaining one. The connection 
between the free end of the anode and conducting cord is made with a 
spring clip, as shown in Fig. 155. 

For labial and buccal surfaces two or more small points to screw 
into a common handle are sufficient (see Fig. 154). These have to be 

Fig. 154. 




Dental anodes for cataphoresis. 



held in situ. A form and arrangement to make these self-sustaining 
offers an important field for inventive skill. 



Fig. 155. 




Snap and wire electrode. 



A convenient cathode electrode is shown in Fig. 156. In this 
the surface is recessed to receive a disk of amadou (spunk) or cottonoid, 



Fig. 156. 




Cathode for cataphoresis. 

one and a half to two inches in diameter, which retains an abundance 
of a solution of sodium chlorid to maintain contact. The surface is 
platinized to prevent corrosion. The reverse side has the usual 
socket to receive the conducting cord, which is placed in a projection 
intended to pass through an opening in the band which supports the 
robber dam. 

It is indifferent where this electrode is placed ; the objects to be 
attained are to lessen the resistance as much as possible and to secure 
constant apposition with the surface with which it is connected. If the 
person be comparatively lean, the face before the ear is to be preferred. 



DENTINAL ANESTHESIA BY CHEMICAL AGENTS. 207 

When there is much adipose tissue on the face, the usual negative hand 
electrode, covered with a small wet napkin to maintain close contact, 
may be better than the application to the face ; but in general the nearer 
the cathode is placed to the angle of the jaw, the quicker and surer is 
the result of the administration. 

The action of cocain administered in this manner is profound. The 
effect is primarily upon the contents of the canaliculi, as is shown in 
the cataphoric treatment of shallow cavities. After superficial anes- 
thesia has been established much lateral cutting will later elicit a degree 
of pain ; in deep cavities nearing the pulp, the effect extends to that 
organ. The recurrence of sensitivity takes place within a few hours. 
No injury appears to follow. 

This method of treatment is little required where the degree of 
hypersensitiveness is such as to yield to desiccation of the dentin or 
the application of carbolic acid combined with caustic potassa (" Eobin- 
son's Remedy "). But when the pain attending excavation requires 
active treatment, such as the employment of zinc chlorid or general 
anesthesia, the cataphoric method is far preferable to either, and is 
nearly certain of giving relief. The results of successful cataphoresis 
are marvellous, and it may be truly stated that no advance of 
recent years in the therapeutic treatment of the teeth is comparable 
to this. 1 

Cautious excavation is required after cataphoric treatment, as in the 
absence of sensitivity indiscriminate cutting may needlessly encroach 
upon the pulp. In case exposure really exists the action of cocain does 
not prejudice conservative treatment of the pulp. When devitalization 
is determined upon, the anesthesia facilitates this procedure. As stated 
in Chapter XVI. cocainization may be then continued either cata- 
phorically or by instillation. Should arsenous acid be selected as the 
devitalizing agent, cocainization may be used as a preparatory measure 
to avoid arsenical irritation. 

The Chemical Treatment. 

Under this head are included the application of warmed air, the use 
of coagulants, notably carbolic acid or zinc chlorid, and, in combination 
with these, one of the essential oils, preferably oil of cloves, for reasons 
stated below. 

Warmed Air. — This method is of great value in subacute cases. 
It is especially serviceable for the cavities of incisors and biscuspids and 
others of easy access. The effect here produced is due to the depriva- 

1 For further study of this subject, see " International System of Electro-Thera- 
peutics," Section C, p. 1 et seq., Peterson; also, "Foundation Principles of Dental 
Cataphoresis," by Dr. Price, Items of Interest, vol. xx. p. 345. 



208 



PRELIMINARY PREPARATION OF CAVITIES, ETC. 



tion of the tissue, to a greater or less degree, of one of its elements, viz. 
water, and it is more effective in teeth of dense structure, since the sur- 
face of these is more easily desiccated than the softer teeth. If it were 
possible to remove all the water of the tissue from the surface to the 
depth of the irritated part all sensitivity would thereby be overcome, but 
generally this can be only imperfectly done ; nevertheless, the benefit 
is generally considerable. This means is easily and quickly applied, 
and as it presents the simplest method in the cases where it is applicable 
it forms therefore the easiest and most available procedure for this 
purpose. 

The warmed air may be produced by heating the bulb of a warm- 
air syringe (Fig. 157) over a lamp or Bunsen burner, when a continu- 

Fig. 157. 




Warm-air syringe. 



ous stream of air is forced through the nozzle into the cavity. Some tact 
is required to deliver the heated air in a manner to cause the least pain 
by its impingement. If the nozzle be held too far away from the tooth 
the stream of air in passing through the atmosphere takes along with it 
so much of the surrounding cool air as to cause pain, and if held too 
close the heat is equally painful. In all cases the abstraction of the 
water, even when the degree of heat is well balanced, produces some 




Electric warm-air syringe. 



unpleasant sensation, which soon passes away and after a few moments 
the case is reduced to a state of slight and simple sensitiveness. The 



DENTINAL ANESTHESIA BY CHEMICAL AGENTS. 209 

blast should be gently applied at first at intervals of a couple of sec- 
onds ; when the pain induced by the abstraction of the water some- 
what diminishes, the force should be increased and made continuous, 
when in most cases the excavation may be continued. The air may 
also and preferably be heated by an electric warm-air syringe (Fig. 
158), which has the advantage of maintaining an even degree of heat. 

As stated before, this means is of less use with soft teeth, and fre- 
quently fails when the teeth have a high grade of sensitivity which 
appears to be due to constitutional conditions, — where the sensitivity is 
not confined to the surface of the tissues immediately beneath the caries 
but pertains to the whole of the dentin. 

Preparatory to the use of heated air, the application to the cavity 
of absolute alcohol is serviceable, on account of its high affinity for 
water. 

Carbolic Acid. — This substance, while of little efficiency in con- 
trolling acute sensitivity, is of benefit in moderating that condition. 
Its efficacy is increased by adding to it a proportion of one-third of oil 
of cloves, which latter has some anesthetic influence. When other 
more active means are not admissible and the effect is not immediately 
satisfactory, a better result is produced by placing this combination in 
the cavity and sealing it in with zinc phosphate until a subsequent 
visit, as before described. On account of the feeble affinity of carbolic 
acid for water, the obtundent effect is facilitated by the previous partial 
desiccation of the surface of the cavity by warm-air blasts. Carbolic 
acid in combination with caustic potassa, equal parts of each (Robin- 
son's Remedy), is often of much service in subacute sensitivity. The 
preparation should be laid in the cavity in contact with the denuded 
dentin and should be allowed to remain until it deliquesces. 

Carbolic acid in combination with tannic acid is also serviceable when 
sealed in the cavity by an impermeable temporary stopping. 

Zinc Chlorid. — Of all substances, when not interdicted by proximity 
of the dental pulp, zinc chlorid is the most efficient of the topical 
remedies for the condition under consideration. Its action is explained 
by the double power of its affinity for water and its extreme coagulating 
effect upon albumin. It is evident that if the tissue be deprived of two 
of its elements the function of sensitivity must be impaired or destroyed. 
In the degree to which this action takes place the tissue loses its capacity 
for irritation. 

As zinc chlorid in concentrated solution is an active escharotic to 
organic tissue, it must be employed with caution. After paralyzing the 
vital resistance of the part its action is by combining in definite propor- 
tions with the albuminous elements of the structure. It has the fur- 
ther property of an excessive affinity for water, which enables one to 

14 



210 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

arrest its action by sufficient irrigation to remove all traces of the salt 
from the cavity. Its active coagulating power renders it a valuable 
agent in excessive dentinal sensitivity where there is not close proximity 
of the pulp, and its safety is ensured by the facility with which any re- 
mains of the salt may be taken up with water. 

Unless employed in excess and too long continued the action of the 
zinc chlorid does not pass beyond the zone of the exalted tissue, which, 
as we are aware, generally is of limited depth. The cessation of the 
pain produced by it indicates the time for its removal, when usually 
the dentin will be found to be insensitive. There are instances, how- 
ever, when no apparent eifect is produced, which can only be satisfac- 
torily explained on the ground that the vital resistance of the tissue is 
sufficient to overcome the coagulative power of the zinc salt. 

In general, zinc chlorid must be regarded as an entirely safe agent 
if used with discretion. It is more applicable to shallow cavities which 
are so situated, or are of such form, as to require much formative cutting 
at the margins of the cavities, as in buccal and labial surfaces and in the 
very superficial cavities of incisors and bicuspids. A warning, however, 
should be presented that as the pulp cornua of incisors frequently pro- 
ject near the surface, particularly in the young subject, considerable care 
is here required in any but shallow cavities of decay. If it were used 
in excess and its action extended there would always be danger, as 
its energies would not cease until the affinities of the whole amount 
were satisfied. In deep cavities the effect, particularly in soft teeth, 
would eventuate in the ultimate devitalization of the pulp. It fol- 
lows, therefore, that it would be improper to seal up any quantity of 
this substance in a cavity. 

The action of zinc chlorid is terminated when the excess is removed 
and the cavity irrigated with water. The affinity it has for water 
quickly removes the excess and soon deprives the tissue of the remain- 
ing portion. 

When cavities are deep and it is found necessary to resort to this 
agent the surface of the deeper parts should be protected by an insoluble 
coating, after which the margins, where the sensitivity is acute, may be 
acted upon without detriment. Here it is requisite to remove the deep 
caries, desiccate the surface and make a coating with a varnish. For 
this purpose red gutta-percha rubbed in chloroform is applicable, since 
it may be deftly applied to any given part and when the chloroform has 
escaped is protective. 

To properly apply zinc chlorid it is highly important to isolate the 
tooth by means of rubber dam to protect the gum and to prevent the 
entrance of moisture. Its affinities for water are so great that even 
the vapor of the mouth dilutes it so much as to lessen its power. The 



DENTINAL ANESTHESIA BY CHEMICAL AGENTS. 211 

form in which it is best to employ it is the saturated deliquesced salt, 
which is taken from a bottle containing the salt in excess. The fluid 
is introduced on a pledget of cotton and is permitted to remain until 
the pain occasioned by it has ceased. It will be found that there are 
two periods of pain : the first from its irritation of the fibrils in the 
bottom layer of the caries, and then again when it has reached the 
zone of exalted dentin a little beneath this ultimate layer of decay. 
It follows, if the caries has all been previously removed and the 
sensitive tissue interdicts further cutting, that but one period of pain 
is encountered. The cutting should therefore be deferred until after 
the second period of pain has passed. The disregard of this considera- 
tion has sometimes cast discredit upon the efficiency of this sovereign 
remedy. 

It is requisite that the chlorid be chemically pure, and the fused 
form is preferable to the crystals of the shops. 

The paix attending the application is sometimes extreme for a mo- 
ment. This can be moderated by air-drying the cavity and dressing it 
with carbolic acid, which does not seem to prevent the action of the 
chlorid. 

To avoid the loss of time which may be occasioned by the slow 
action it is advisable, after securing the dam at the neck of the tooth 
by a ligature, to very tightly tie the free portion of the rubber a short 
distance from the tooth w T ith a strong ligature, and after cutting away 
the excess of rubber some other service may be rendered. When the 
pain has ceased the case may be proceeded with, or the excess of chlorid 
may be thoroughly washed out and the cavity temporarily closed until 
a subsequent time. 

Another method of securing the action of zinc chlorid is to make a 
paste of zinc oxychlorid and fill the cavity with it. Even after crys- 
tallization of the paste takes place it contains a slight excess of the 
chlorid, which slowly acts upon the hypersensitive tissue. This method, 
however, is not adapted to deep cavities, and care must be exercised con- 
cerning its use in teeth of inferior grade. 

Zinc chlorid is an extremely valuable remedy when the previously 
described agents prove insufficient or are not indicated. 

Conditions which render Zinc Chlorid inadmissible. — It has been 
stated that the chief danger of its use consists in the liability of the 
coagulant and escharotic action reaching the pulp in deep cavities. 
This danger is further enhanced when the teeth are soft, as in this con- 
dition the penetration is liable to be greater than would be the case with 
dense dentin. The same caution must be observed when the structure 
is incomplete, as it is in the teeth of young subjects. Even here, as 
extreme sensitiveness is always found at the peripheral limits of the 



212 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

tubules, it is not difficult to limit the action to this part by the means 
above pointed out if care be taken in the required procedures. 

The Acids. — Chromic and nitric acids are of service in extremely 
shallow cavities of very high sensitivity. The former acts by coagula- 
tion of the organic elements of the dentin and the latter by decomposi- 
tion and solution. To apply these the adjacent tissues require to be 
protected. Each should be carried in small quantity upon a gold 
probe. 

Nitrate of silver is applicable for reducing the sensitivity of dentin 
after the removal of superficial caries or when by abrasion or by erosion 
the exposed tissue is intolerably sensitive. It is, however, only to be 
used in the back of the mouth on account of the discoloration which it 
produces. 

Chlorid of antimony is applicable only to cases of exposed cemen- 
tum, where it is claimed that it is equally as efficient as silver nitrate, 
and has not the objection of discoloring the tissue. 

General Anesthesia. 

While some reluctance should exist as to the propriety of inducing 
general anesthesia, it sometimes becomes necessary to resort to this 
means of alleviation. Necessity for this election arises where the sen- 
sitivity is extreme, when the previous remedies have been inefficient, 
and when from the nature of the case zinc chlorid is inadmissible. 

The subjects should generally be adult persons of intelligence, who 
possess moral force and, having confidence in their adviser, are capable 
of giving the requisite indications of the progress of the anesthetic 
influences. 

Sulfuric ether is the most suitable anesthetic to be employed, and 
the operative procedures should be performed in the first stage, that 
of peripheral anesthesia. At this period, which is before the stage 
of excitement commences, dentin may be cut without the slightest 
pain being felt. This is an important consideration, since if the ad- 
ministration is continued into the period of excitement nothing can be 
done, and if it is conducted to a full degree the patient is not manage- 
able. Also the subsequent depression is to be avoided. While general 
anesthesia in the first stages is available for the relief of dentinal sensi- 
tivity, it is found, on the contrary, when resorted to for the removal of 
the pulp, as may occasionally be required in the most severe cases of 
congestion, that nothing short of profound anesthesia will suffice. 

When the first stage is reached, the patient being conscious and able 
to reply to questions, the cutting is commenced ; as the pain returns a 
few more inhalations are given, when another part of the cutting may 
be proceeded with. This may be repeated until the cavity is formed. 



GENERAL ANESTHESIA. 



213 



Fig. 159. 



The cutting should be quickly and deftly conducted. The amount of 
ether administered is far less than is required to induce full anesthesia, 
and the patient suffers far less depression than if the operation were 
performed without this means. There is also no danger of shock, since 
the patient is, or should be, intelligently concerned in the progress of the 
case. If the condition were carried into the second stage, when excite- 
ment exists and alarm is aroused in addition to the operative interfer- 
ence, there is liability to shock, which, being due to a profound impres- 
sion on the nervous system, is not liable to occur when the patient 
concurs in all the steps of the procedure. 

The time required to bring about a sufficient degree of dentinal 
anesthesia frequently is less than two minutes. The ether should be 
pure and should be given with a free supply of air mixed with the 
vapor. The ordinary custom of using the towel to envelop the face is 
questionable, since this method does not permit enough air to accompany 
the ether vapor. 

An invaluable inhaler for this purpose is the one invented by Dr. 
Allis (Fig. 159). This consists of an oval 
frame composed of a series of wires through 
which passes back and forth a continuous 
band of muslin. The layers of muslin 
are near each other, and still so far apart 
as to permit the free passage of the at- 
mosphere. The correct manner is to 
continuously drop the ether in small 
quantity upon the muslin to maintain it 
at an even degree of saturation. 

This appliance is one of value to the 
dental operator, as by it the anesthetic 
state can be more quietly brought about 
with less of the characteristic disturb- 
ances which attend the usual modes of applying sulfuric ether. 

The use of chloroform for the purpose under discussion is wholly 
inadmissible. 

The mechanical means consist in the use of temporary fillings, 
which may be either metallic or non-metallic. The metallic act by 
inducing, in consequence of the slight irritation of thermal conductivity, 
a consolidation of the subjacent dentin, which in time obliterates the 
tubules. The non-metallic act simply as a protective covering to the 
denuded dentin. Their action hence is more tardy than that which 
follows the use of the former. 

The metallic stoppings for this purpose may be composed of either 
tin foil or amalgam. Each of these requires cavities of reasonably good 




The Allis inhaler. 



214 PRELIMINARY PREPARATION OF CAVITIES, ETC. 

retentiveness, therefore they are not applicable to shallow cavities of 
unsuitable form. 

The non-metallic may be either gutta-percha, zinc phosphate, or zinc 
oxychlorid. The two latter are the most desirable, as they adhere 
to any well-dried cavity, and having some irritating influence on 
the tissues tend to induce structural consolidation in addition to their 
protective action. They have, however, the disadvantage of suffering 
loss by chemical solution, and unless kept under close observation are 
delusive and in many instances are a deceptive means of preventing the 
recurrence of decay. In the employment of these substances due care 
should be exercised concerning the proximity of the pulp, in which cases 
the previously indicated means of shielding the pulp walls should be 
pursued. 

The chief disqualification of gutta-percha is its lack of resistance to 
attrition, and when in positions shielded from wear it may be attacked 
by low forms of bacterial life, which disintegrate it. 

Mechanical protection of cavities is most applicable to teeth of a low 
grade of structure and for young children who may not have the ability 
to tolerate the more active means needed to reduce dentinal sensitivity. 
For these cases gutta-percha stoppings when carefully introduced are a 
great boon, since they protect the tissues during the period of completion 
and consolidation of the teeth. 






CHAPTER VIII. 

PREPARATION OF CAVITIES— OPENING THE CAVITY— RE- 
MOVING THE DECAY— SHAPING THE CAVITY— CLASSI- 
FICATION OF CAVITIES. 

By S. H. Guilford, A. M., D. D. S., Ph. D. 



General Considerations. — The importance of the proper preparation 
of a cavity for the insertion of a filling can scarcely be overestimated. 
Upon its being well done the success of the completed operation largely 
depends. As many fillings fail from lack of thoroughness in the pre- 
paration of the cavity as from any other cause. 

The operator should not be actuated by haste, but should be deliber- 
ate, careful, and painstaking. Each stage of the operation should be 
thoroughly performed in order that when completed the cavity may be 
in the best possible condition for the reception and retention of the 
filling. 

The operation is naturally divided into three stages : 

1. Opening the Cavity. 

2. Removing the Decay. 

3. Shaping the Cavity. 

Opening the Cavity. 

Every cavity to be excavated must first be opened, so that it may be 
approached and operated upon at all points. The particular manner of 
doiug this will have to be determined by the extent of the decay and its 
position, but in all cases the opening must be as full and free as the 
conditions will permit. 

The accessibility of the cavity will depend upon its location. Upon 
the three exposed surfaces of a tooth crown (occlusal, lingual, and labial 
or buccal) access to a cavity is usually easy, but upon the unexposed 
surfaces (approximal) access can only be had after the teeth have been 
pressed apart. For methods of securing temporary separation of the 
teeth see Chapter VI. 

A cavity upon an exposed surface, if small, can usually best be 
opened by the use of some form of engine bur. A few sizes each of 
the forms known as " fissure," " inverted-cone/' and "round" (or 

215 



216 



PREPARATION OF CAVITIES. 



" rose-head ") are shown in Figs. 160-162. A spear-pointed drill 
is sometimes used, but is less serviceable on account of its tendency 
to be caught or broken in the irregularities of the cavity orifice. A 
modified form of fissure bur has found much favor in the opening of 
small cavities on exposed surfaces. It is made from an ordinary bur 



Fig. 160. 



Fig. 161. 



Fig. 162. 






Fissure burs. 



Inverted-cone burs. 



Round burs. 



from which the head has been broken, by cutting spiral blades on the 
tapering neck of the shank. Being pointed, round, and tapering it 
easily effects an entrance into the cavity and enlarges the orifice grad- 
ually and symmetrically. It is shown in Fig. 163. 

In cavities of larger size, where decay has made more progress, the 
overhanging walls of enamel can best be broken down by chisels of 
suitable size and form. Where a straight chisel can be employed it 
will be found most efficient, but in positions difficult of access one 
having a slight curve or angle may need to be employed. Figs. 164 and 
165 represent both forms as well as the sizes usually preferred. The 



Fig. 163. 



Fig. 164. 





Modified fissure bur with 
tapering point. 



Straight chisels. 



Curved chisels. 



width of the blade may vary from one-sixteenth to one-eighth of an inch, 
but wider ones than these Avill seldom be required. 

A chisel may be used with either hand pressure or mallet force. If 
the former, great care must be exercised to prevent its slipping and 
causing pain or possible injury. The best safeguard in its use is to 
place the thumb of the right hand on the tooth being operated upon or 
some adjoining one and use it as a fulcrum or pivot upon which the 



REMOVING THE DECAY. 



217 



instrument may move in a curve. By this means the motion of the 
chisel is regulated and controlled and all danger of slipping avoided. 
It will sometimes be of advantage to roughly pack the interior of the 
cavity with cotton or spunk to receive the impact of the instrument 
should the chisel accidentally be forced to the bottom of the cavity. 

The better plan, however, in most cases, is to employ mallet force 
for the cleavage of enamel unsupported by dentin. By holding the 
chisel between the thumb and three fingers of the left hand and resting 
the little finger of the same hand on an adjacent tooth for steadiness, a 
smart but light blow of a mallet in the right hand upon the end of the 
chisel will easily and painlessly cleave off portions of the enamel. 

In opening cavities of small extent or limited depth upon approxi- 
mal surfaces a round or inverted-cone bur will best 
serve the purpose, but where caries is more exten- 
sive and the surrounding enamel is unsupported by 
dentin the orifice of the cavity can be more advan- 
tageously enlarged by means of a delicate chisel 
(shown in Fig. 1 66) the blade of which is bent at a 
slight angle to the shank and all three of the edges 
of which are bevelled to convert them into cutting 
edges. This instrument will be found especially 
useful in opening cavities of medium or larger size 
on the approximal surfaces of the incisors, the point 
doing the cleaving and the side edges being used to 
smooth the enamel margins. 

After the orifice of the cavity has been sufficiently 
enlarged to afford a full view of its interior the next 
stage of the operation is entered upon — 



Fig. 166. 

8 



Delicate three-sided 
chisel, useful for 
opening cavities on 
approximal sur- 
faces. 



Removing the Decay. 

The character or consistence of the carious structure has much to 
do with the method and means employed for its removal. If it be of 
the semi-elastic or leathery variety so often found in the teeth of young 
persons, it can be most easily removed by means of spoon-shaped or 
round-bladed excavators, which being oval or circular in edge out- 
line and free from marginal angles, will lift and separate the layers 
without danger of injuring the underlying healthy dentin and with the 
infliction of a minimum amount of pain. Fig. 167 illustrates this kind 
of instrument in some of its forms, selected from the Darby-Perry set. 

In the dark, hard variety of caries, as also in the white, chalky 
variety, the different forms of burs and excavators will be found best 
suited for the purpose. 

In the removal of caries care should be exercised to inflict as little 



218 



PREPARATION OF CAVITIES. 



pain upon the patient as possible. To this end, in cavities of con- 
siderable extent, it is best, after the orifice has been sufficiently enlarged, 
to make a sweeping cut with an excavator around the cavity just below 



Fig. 167. 



J I ) M 




Excavators. 



the enamel line, thus freeing the decayed portion at that point. Follow- 
ing this the remaining portion of carious dentin should be removed by 
placing the blade of the excavator near the bottom of the cavity and 
making draw-cuts toward the orifice. To cut in the reverse direction 
would produce uncomfortable pressure upon the most tender portion of 
the cavity, and possibly, by inadvertence, expose and wound the pulp. 
When burs are employed for the removal of caries it is safest to use 
only such as are more or less rounded on their circumference, such as 
the round or oval forms, for they more nearly conform to the natural 
outline of the cavity, leave no angular grooves in the dentin difficult 
or impossible to perfectly fill, and are not so likely to injure the healthy 
subjacent dentin. 

The varieties of bur known as the inverted-cone and wheel, while very 
useful for opening cavities, should not be used for the removal of caries 
in deep cavities, because of the irregularities of surface which their 
peripheral angles produce. 

Rapidly revolving bars in an engine handpiece are very apt to cause 
pain by the development of factional heat. This may largely be pre- 
vented by lifting the bur at short intervals and allowing it to run free 
for a moment, which will prevent overheating the tooth and thus avoid 
unnecessary pain. 

Thorough excavation of the cavity and the removal of all carious 
dentin is absolutely essential to success. To allow any portion of it to 
remain and trust to the employment of germicides for its sterilization 
is running the risk of failure, for we can never be entirely sure of 
disinfection. Besides this, there is no good reason for allowing cari- 
ous dentin to remain. 

By carious dentin is meant the remains or debris of the action of 



REMOVING THE DECAY. 219 

caries, — a product resulting from this disintegrating action upon both 
the organic and inorganic constituents of dentin. In nearly all cavi- 
ties we find two varieties of altered tissue. That nearest the surface is 
a mass of thoroughly disorganized and usually decomposed matter filled 
with micro-organisms. Beneath this and lying next to the healthy den- 
tin there is a zone or layer from which the calcium salts have been re- 
moved by the acid solvent, but which still retains its original form and 
vitality. This layer of decalcified dentin may be allowed to remain, 
especially in the bottom of a cavity, as it serves to protect the subjacent 
tissue from thermal shock and will in the great majority of cases be 
again converted into normal dentin by the re-deposition of calcium salts. 
As a precautionary measure, however, it should be treated to an applica- 
tion of some germicide such as carbolic acid, mercury bichlorid, for- 
malin (10 per cent, aqueous solution), or oil of cinnamon, before the 
insertion of the filling. 

Occasionally caries will be found to be self -limited. In such 
cases, through some unexplained change of conditions, the progress 
of caries has been checked and the layer of decalcified dentin re- 
stored to its previous normal condition. Where this has taken place 
the restored tissue is usually of a darker color than ordinary dentin, 
and on this account may be mistaken for carious dentin and removed. 
It is, however, easily distinguished from caries by its hardness, and 
should in no case be removed except from the sides of a cavity, and 
then only when its dark color showing through the walls would prevent 
the cavity, after being filled, from having that clear and clean appear- 
ance which it should possess. 

With some practitioners it is the custom to prepare a cavity dry, 
because in this way the operation is more rapid and usually less painful. 
In such case the rubber dam is applied first of all and the operations of 
opening, cleansing, and shaping the cavity are all performed without 
the presence of moisture. Repeated applications of warm air from a 
syringe, at intervals during the operation, desiccate the dentin and di- 
minish its power of sensation. Others, in order to avoid the unpleasant- 
ness to the patient of having the dam in position for so long a time, 
prepare the cavity roughly in the presence of moisture, then apply the 
dam, dry the tooth thoroughly, and finish the operation. 

Whichever plan is adopted it is absolutely necessary, in all cases, to 
finish the preparation with the dam on and the tooth dry, for it is only 
after a tooth has been deprived of its moisture that we are able to 
decide whether all the niceties of preparation have been successfully 
carried out. Certain marginal and structural defects that are not 
noticeable while the tooth is moist are plainly revealed after it has been 
dried. 



220 PREPARATION OF CAVITIES. 



Shaping the Oavity. 



This is one of the most important of all operations associated with 
the stopping of a cavity, for according as it is properly or improperly 
performed will success or failure result. Too much stress cannot be 
laid upon its importance, nor too great care be exercised in its accom- 
plishment. 

Inasmuch as a filling is retained in place mechanically it follows that 
the cavity must be of such shape as to favor retention. To this end it 
should be larger within (at least at certain points) than at the orifice. 
An exception to this rule lies in such cavities as are of small diameter 
and of more than moderate depth. In cavities of this character, 
parallel walls will suffice, because lateral-surface contact is so great in 
proportion to the mass to be held in place that displacement could not 
occur. In larger cavities of moderate depth, however, the reverse is 
the case, and they will require the assistance of internal enlargement 
for the retention of the filling. To govern each of the conditions two 
rules may be formulated : 

1. When the depth of the cavity is greater than the diameter of the 
orifice, parallel lateral walls will prove retentive. 

2. When the diameter of the orifice is greater than the depth of the 
cavity, the latter will have to be somewhat enlarged internally to retain 
the filling. 

Examples of the first class are found in the narrow but rather deep 
cavities which occur on the lingual surfaces of the upper incisors 
near the cervix ; in the pit cavities on the buccal surfaces of molars ; 
and in the small cavities found on either side of the enamel ridge on 
the occlusal surfaces of the lower first bicuspids. 

Examples of the second class are found in numberless places on any 
of the crown surfaces. 

In some cases cavities will be found of such form that when the 
decay has been removed they will have a naturally retentive shape, but 
in the great majority of cases more or less sound tissue will have to be 
removed in order to give them the required form. To give a cavity a 
retentive form it is not necessary that its interior be enlarged throughout 
its whole extent, but it must be larger at two or more points, and these 
points must be opposite one another. Frequently it will be easier to 
enlarge the cavity at all points, and to this no objection can be urged 
provided too much sound tissue be not removed or the pulp be not too 
nearly approached. Too great enlargement tends to weaken the cavity 
walls and therefore should be guarded against. 

In shaping the cavity internally instruments should be employed 
that will leave the surface free from angles, for the filling material can- 



SHAPING THE CAVITY. 



221 



not be perfectly adapted to them. As in the removal of decay, excava- 
tors for this purpose should have curved edges, and burs should be of 
a round or oval form. 

If grooves are required they should neither be made deep nor too 
near to the enamel, for fear of weakening the walls. At the cervical 
margins of cavities grooves and starting pits should be avoided when- 
ever possible, for they weaken the portion of the cavity which is sub- 
jected to the greatest strain in the introduction of the filling, both 
mechanically and by cutting off the nutrient supply to the cervical 
margin, which tends to alter the resistive character of that portion of 
the tooth structure by devitalizing it. 

For the same reasons deep grooves or undercuts should not be made 
near the incisal or occlusal surfaces, for the strain of mastication will be 
liable to result in fracture of the wall if it is thus unduly weakened. 

In the process of shaping the cavity internally the enamel margins 
will naturally be assuming their proper form, but the final part of the 
preparation should consist in giving these frail portals of the cavity 
very careful and minute attention. 

The value and permanency of a filling will largely depend upon the 
strength of the enamel walls and their proper preparation. The enamel 
cap of a tooth when intact is exceedingly strong and capable of resist- 
ing great strain, but when its continuity has been broken by caries and 
it is left unsupported by dentin it is very weak and brittle. This is 
readily understood when Ave remember that enamel is composed of an 
aggregation of enamel rods or prisms in close juxtaposition, slightly 
joined together by a cementing substance, with their greater diameters 
perpendicular to the plane of the surface of dentin upon which they 

Fig. 168. 




Showing enamel structure. 

rest. When continuous, these rods mutually support one another and are 
thus capable of resisting great strain ; but when a lesion has occurred 
they lose support on the adjoining side and hence are easily separated 
in the direction of their length. Fig. 168 (after Black 1 ) shows this 

1 Dental Cosmos, vol. xxxiii. p. 441. 



222 PREPARATION OF CAVITIES. 

condition perfectly. A detached section of enamel prisms is represented 
at a, and at b is shown a portion about being separated by a chisel. 

This will explain why enamel unsupported by dentin should not be 
allowed to form the margin of a cavity, for it will probably either be 
fractured while the filling is being introduced or afterward in mastication. 
On all convex surfaces of a tooth the enamel rods radiate outwardly, 
and by forming the margins of a cavity on these lines it will have a 
slightly flaring or trumpet-shaped orifice, which will not only afford the 
greatest strength but will admit of a better finish being given to the edges 
of the filling. In many cases it will be necessary to give the margins of 
a cavity more of an outward bevel than would be obtained by simply 
following the cleavage lines of the enamel rods. This can be secured 
by cutting away the outer ends of the enamel rods in an oblique direc- 
tion as shown at c in Fig. 168. No weakening of the border will result 
in such cases, inasmuch as the shorter rods will still rest upon the 
dentin. If, however, the rods were cut so as to leave only their outer 
ends in place, as shown at d, they would have no substantial support, 
and would be liable to be crushed daring filling or afterward. All 
cavity margins should have the outward bevel to a greater or less 
extent in order to secure the best and most permanent results. 

In cavities upon depressed or concave surfaces of teeth it would not 
do to have the enamel margins formed on the lines 
of enamel cleavage, for this would make the margin 
of the orifice the most contracted portion and result 
in frail marginal edges. Fig. 169, representing a 
cross section of a bicuspid tooth with a cavity in the 
bicus- SU J CUS > wil1 illustrate this point : A shows the cavity 
pid showing treat- orifice prepared on the lines of enamel cleavage, 

ment of enamel mar- i r\ ~\ • r\ > ^ p 1 

' gins of cavity in the an( l B the dressing across the outer edges of enamel 
sulcus, required to give the necessary strength. 

It may therefore be laid down as a rule that to secure the best results 
the line of a cavity wall from within outward should form with the surface 
of the tooth at this point an obtuse angle. 

Beside the proper shaping of a cavity margin it should also be made 
as smooth as possible. In accessible cavities upon exposed surfaces of 
teeth the final marginal smoothing or finish can best be effected by the 
use of a bur shaped somewhat like a fissure bur, but having a rounded 
end and being simply file-cut upon its surface instead of being bladed. 
Such a one is shown in Fig. 170. Its sides being parallel, no rounding 
of the cavity margins can occur when it is used with the end inside of 
the cavity. Any other form of bur with a short head would unavoidably 
give to the cavity margin either a concave or a convex surface, both of 
which would be incorrect. 




CLASSIFICATION OF CAVITIES. 



223 



The buccal, lingual, and cervical margins of a compound approximal 

cavity should never be finished with a bur, even of the plug-finishing 

variety, but should be smoothed with suitable chisels, broad-faced 

excavators, or approximal trimmers, the latter being shown in Fig. 171. 

Fig. 170. Fig. 171. 



File-cut enamel finishing bur. Approximal trimmer. 

The practice of finishing cavity margins with sand-paper disks, 
Hindostan-stone points, or wooden points charged with emery powder is 
very objectionable, as they are almost certain to give to the margins a 
rounded edge which cannot be filled and finished without leaving a 
feather edge of the filling overlying the enamel, which will eventually 
be broken off or flared up, leaving an imperfect margin. 

Classification of Cavities. 1 
I. Simple Cavities on Exposed Surfaces. 
Bicuspids and Molars. Incisors and Canines. 

A. Occlusal. D. Labial. 

B. Buccal. E. Lingual. 
C. Lingual. F. Incisal. 

II. Simple Approximal Cavities. 
Incisors and Canines. Bicuspids and Molars. 

G. Mesial and distal. H. Mesial and distal. 



III. 


Compound Cavities. 


icisors and Canines. 




Bicuspids and Molars. 


I. Mesio-labial. 




P. Mesio-occlusal. 


J. Disto-labial. 




Q. Disto-occlusal. 


K. Mesio-lingual. 




R. Occluso-buccal. 


L. Disto-lingual. 




8. Occluso-lingual. 


M. Mesio-incisal. 




T. Mesio-disto-occlusal 


N. Disto-incisal. 






0. Mesio-disto-incisal. 





1 Following the suggestion of Dr. Black, in the above list the word lingual is used 
for the same surfaces in both the upper and lower teeth, doing away with the word 



224 PREPARATION OF CAVITIES. 

In the foregoing classification the cavities have been arranged pro- 
gressively from the simplest (A) to the most complicated (T). 

I. Simple Cavities on Exposed Surfaces. 

BICUSPIDS AND MOLAKS. 

Class A. — Cavities upon the occlusal surface are very accessible and 
in full view, enabling the operator to see every part of the cavity and 
affording him plenty of room in which to operate. Naturally those 
nearest the front, as in the bicuspids, present the advantage of greater 
accessibility, but none of them are difficult to prepare and fill except 
under unusual conditions. 

Usually the first part of a bicuspid crown to become affected by 
caries is the fissure between the cusps. Sometimes it presents merely as 
a black line into which only the point of an explorer will penetrate ; 
at a later stage the cavity is more fully defined by the greater pro- 
gress of caries and the crumbling of the walls of its orifice. In the 
first instance the cavity is most readily and comfortably opened by 
means of the tapering fissure bur shown in Fig. 163. After passing it 
into one of the terminal pits of the cavity it may be drawn along toward 
the other, opening the fissure quite freely. Once open, the decay may 
be removed and the cavity shaped by a suitably sized round bur 
(Fig. 162). As the decay has usually progressed farther in the region 

of the terminations of the cavity than in 
Fig. 172. ^ e S p ace between them, the cavity when 

fully formed will be oblong in shape and 
contracted in the centre. In Fig. 172, 
A shows this form, while B represents 
the same surface before being- operated 

Cavity in sulcus of a bicuspid. ° L 

upon. 

In preparing the cavity no more sound tooth-structure should be 

sacrificed than is absolutely necessary, but every portion of decay should 

be thoroughly removed and particular attention be given 

to opening up the minor fissure terminations as shown at 

A A, b b (Fig. 173). 

When completed, the cavity should be very slightly 
larger within than without, the margins should present 
no angles, but only a series of curves in outline, and the 

The fissure & J # ' 

terminals. marginal edges should be slightly bevelled outwardly. 
Bicuspid cavities of this character vary in size according to the extent 
of decay, but the essential features in each case are very similar. The 

palatal. In the forming of compound terms, where the medal or distal surfaces are 
included, these terms precede the others. Where they are not included and the word 
occlusal is used, it is given first place. 






SIMPLE CAVITIES ON EXPOSED SURFACES. 225 

lower first bicuspid differs normally from all others of its kind in 
having no sulcus and consequently no fissure between the cusps. In- 
stead of the two cusps being separated by a sulcus they are united by 
a ridge of enamel. (See Chap. I., p. 35.) The only points, therefore, 
that invite decay upon the occlusal surface of this tooth are the two 
pits that are found one on each side of the ridge. These are to be 
filled separately. They probably represent the very simplest form of 
simple cavities to be found anywhere in teeth. 

The occlusal surface of an upper first or second molar presents two 
points liable to decay. One is a pit formed by the junction of two 
small fissures near the mesial margin, and the other is a fissure which 
runs between the disto-buccal, disto-lingual, and mesio-lingual cusps. 
Both are represented in Fig. 174. When limited in extent they should 
be opened in the same manner as a bicuspid fissure cavity, but when 
larger they may be opened by means of a chisel followed by a suitable 
bur. In these, as in all cavities in sulci, the fissures must be followed 
and opened up to their extremest limits in order to ensure success, while 
the margins and marginal edges must be so formed as to be strong, 
smooth, and bevelled. 

The general form of these cavities when prepared is shown in 
Fig. 175. It will frequently be found that these two occlusal cavities 

Fig. 174. Fig. 175. Fig. 176. Fig. 177. 







Molar fissure cavities. Molar fissure cavities prepared for filling. 

are joined underneath, while near the surface they are separated by a 
ridge of enamel and dentin. In such cases the ridge should be cut 
away and the two cavities converted into a single larger one as illus- 
trated in Fig. 176. 

If the ridge were allowed to remain it would almost certainly be 
fractured either in the operation of filling or subsequently by the force 
of mastication. 

The upper third molar differs from those anterior to it in having 
but three cusps and consequently but one central pit with radiating 
fissures. A cavity occurring here when properly prepared will pre- 
sent a triangular outline with rounded angles, as in Fig. 177. The 
terminals of fissures should always be finally finished with a round bur 
to prevent any possible angles and opportunity for leakage at those points. 

The lower first molar, as well as the third, having five cusps with 
intervening sulci, a cavity upon this surface will be pentagonal in out- 
line, as represented in Fig. 178. 

15 



226 PREPARATION OF CAVITIES. 

Extreme care should be exercised in preparing cavities of this 
character to insure that the fissures running between the buccal cusps 
are fully opened and cleared of every particle of decay and discolora- 
tion. Too often this is overlooked and caries supervenes. 

The lower second molar with its four cusps has two sulci inter- 
secting each other at a right angle. Decay usually begins at the inter- 
section and extends along the radiating arms of the fissures. If the 
cavity were prepared by cutting out the fissures only it would yield a 
crucial-shaped cavity with four sharp or nearly sharp angles at the 
intersection, as shown in Fig. 179. Owing to these angles of dentin 

Fig. 178. Fig. 179. Fig. 180. 





Lower first molar with stel- Lower second molar with Prepared cavity in lower 

late cavity. Prepared. crucial cavity. Not pro- second molar. 

perly prepared. 

and enamel the perfect filling of the cavity would be exceedingly 
difficult. 

The case may be simplified and better results in every way obtained 
by rounding these angles and giving the cavity a form like the one 
shown in Fig. 180. 

Class B. — Buccal cavities are seldom met with in the bicuspids 
except at the cervix. In this location they possess the same features as 
the similar class of cavities occurring on the labial surfaces of the 
incisors. Their treatment will be described under class D. 

The upper molars also are seldom found decayed on the buccal sur- 
face except at the cervical border. Cavities occurring at this point are 
usually narrow and long, following the outline of the gum. They can 
best be prepared with an engine bur of suitable form, and if occurring 
on the second and third molars a right-angle attachment may have to 
be employed to reach them conveniently. Decay at this point is often 
of the white variety, and as it so nearly resembles the natural color 
of the tooth extreme care will have to be exercised to include all of 
the decalcified portion within the limits of the cavity. A retentive 
form is most conveniently given to these cavities by slightly undercut- 
ting them in the direction of their length. In the third molars it is 
sometimes advisable to make an undercut or starting-pit at the distal 
end for the beginning of the filling. 

Sometimes a small cavity will be found at about the centre of the 
buccal surface of the upper molars, but far more frequently a cavity 
of greater extent will be found upon the same surface of the lower 
second molar. It originates in a pit at the termination of the fissure 




SIMPLE CAVITIES ON EXPOSED SURFACES. 227 

running over from the occlusal to the buccal surface between the two 
buccal cusps. Oftentimes the cavity is so large as to include the greater 
portion of this surface of the tooth. Its usual form and appearance are 
shown in Fig. 181. 

Not infrequently this cavity is compounded with one on the occlusal 
surface. In opening and preparing it a slightly undercut 
form is readily given to it. 

Class C. — Decay rarely occurs upon the Ungual sur- 
faces of molars on account of their smoothness and con- 
vexity and because they are more or less constantly rubbed Buccal cav i t y 
by the tongue in speech and mastication. The evenness of in lower sec- 
this surface is, however, broken in the upper first and sec- 
ond molars by a fissure extending over from the occlusal surface and 
passing between the two lingual cusps. (See Chap. I., p. 39.) This fis- 
sure is deeper and more pronounced in the first molar, but in each tooth 
it is generally the seat of caries early or later in life. In the majority 
of cases this fissure is decayed throughout its entire length, forming a 
compound cavity, but occasionally only the pit at its termination on 
the lingual surface is affected. 

Another point on the lingual surface liable to decay is on or near the 
mesio-lingual angle of the upper first molar, about midway between the 
cervical and occlusal margins. At this place is often found a supple- 
mental cusp, diminutive in size, and where it joins the main surface of 
the tooth a small fissure exists which invites decay. This 
additional cusp, when it does exist, is found only upon the FlG# 182, 
first molar. It is shown at A in Fig. 182. (See Chap. 
I., p. 39.) Neither of these cavities presents any diffi- 
culties in preparation except such as occur from their slight 
difficulty of access. 

Occasionally, though very rarely, the lingual surface 
of any of the molars may present a cavity of decay close 
to the gingival line and partly beneath it. Such cavities are doubtless 
caused by the retention of food debris beneath the free margin of the 
gum, and owing to their position they are difficult to treat. They 
should be opened and packed over-full with cotton and varnish or 
gutta-percha for a day or two, to press the gum away, after which they 
may be prepared and filled in the usual manner. 

INCISORS AND CANINES. 

Class D. — Cavities upon the labial surfaces of incisors and canines 
are usually found along the gingival margin, and are the result of the 
direct action of acids probably formed at this point. In the beginning, 
and when small, they are entirely exposed, but when of greater extent 




228 PREPARATION OF CAVITIES. 

they frequently extend beneath the free margin of the gum. They are 
nearly always elliptical in outline and may consist of simple decalcified 
enamel still retaining the usual surface form, or they may possess the 
common characteristics of cavities in general. 

The opening and preparation of this class of cavities are not attended 
with any marked difficulties except that when they extend beneath the 
gum care will have to be exercised not to wound this tissue, as the 
consequent bleeding would obstruct the view and interfere with the 
progress of the work. This may be prevented by pressing and holding 
the gum away with a suitable instrument held in the left hand while the 
cavity is being prepared. Particular attention should be paid to the care- 
ful preparation of the cervical margin of the cavity and to its terminal 
points. The former should be made smooth and even, and the latter 
should be extended far enough to include any enamel that shows the 
least sign of acid alteration. Slight grooves or enlargements at the 
base of the cavity along its upper and lower margins will give it a suf- 
ficiently retentive form. 

A second locality on the labial surface where decay is frequently 
found is anywhere between the central portion and the incisal edge, 
in pits and depressions that indicate imperfect development of the 
enamel. These pits or grooves extend in a nearly straight line parallel 
to the incisal edge, and are frequently the seat of decay. 

When quite shallow they may be obliterated by grinding the surface 
with a small corundum wheel and polishing, converting the 
surface at this point into a distinct concavity. When the 
pits are deeper and isolated they may be filled separately, 
the result being a lesser degree of conspicuousness ; but 
when they are connected by a groove, as they usually are, 
Pitted incisor, they will have to be converted into a single cavity and 
filled. A common type of this defect is shown in Fig. 1 83. 
When these pits occur upon the incisal edge or in close proximity 
to it the choice lies between an unsightly gold filling, a porcelain tip, or 
their removal by grinding and the resultant shortening of the crown. 
Class E. — There is usually but one point upon the lingual surface 
of incisors and canines that is liable to decay. It is in the pit at the 
junction of the basilar ridge or cingulum with the adjacent tooth 
surface. The incipiency of caries at this point presents only as a mi- 
nute cavity, the opening and shaping of which is readily accomplished 
with a round bur. Although the orifices of these cavities may be 
small, the dark spot that marks their direction is often continued quite 
a distance toward the pulp chamber. This black point should in all 
cases be followed to its termination and obliterated. It will never be 
found to reach the pulp or to approach dangerously near it. As the 





SIMPLE APPEOXIMAL CAVITIES. 229 

depth of these cavities is greater than the diameter of their orifices, no 
special retentive shape need be given them. 

The orifice should always be bevelled and enlarged, if necessary, to 
include any neighboring fissures. 

When these cavities are of greater extent they are prepared and 
filled like others of similar size and form. 

Class F. — Cavities upon and confined to the incised edge of incisors 
and canines are easily prepared on account of their accessibility. This 
particular surface should, and generally does, remain free from decay 
on account of the attrition to which it is constantly subjected ; but 
when defects in the enamel exist, caries sometimes occurs in connection 
with it. 

This surface often needs covering with gold to check abrasion in 
cases where, after middle life, the crowns (especially those 
of the upper teeth) have been shortened by excessive 
wear. Under these conditions the surface has to be so 
prepared and shaped as to retain the gold that is to cover 
and protect it just as though caries had originally injured 
the part. In forming the cavity in the exposed dentin 
it is only necessary to cut deeply enough to afford a lodg- 
ment for the filling, but the orifice must be so enlarged and Cross 
excessively bevelled as to reach to the marginal edge of cavity on in- 
enamel all around. This is done to protect the enamel 
from chipping or fracture in mastication. To afford the greatest 
security to the filling the cavity should be undercut throughout its 
whole extent. When thus prepared, the cavity in cross section will 
resemble a double dove-tail as shown in Fig. 184. 

II. Simple Approximal Cavities. 

INCISOKS AND CANINES'. 

Class G. — Cavities upon the mesial and elisted surfaces of the 
anterior teeth present only the difficulty arising from inaccessibility. 
To reach and operate upon these cavities, the teeth, if in normal contact, 
will usually have to be pressed apart either by gradual wedging or by 
immediate separation with a " separator." Even after this has been 
accomplished the cavity cannot be operated upon in a direct way as are 
cavities upon exposed surfaces, but will have to be approached from 
either the labial or lingual aspect of the crown. To do this, if the 
cavity be small, will generally necessitate an additional enlargement of 
the cavity toward the surface from which it is to be approached. As 
the lesser of two evils the enlargement is usually made toward the 
lingual surface, for in this way the exposure of gold when the filling is 



230 



PREPARATION OF CAVITIES. 



Fig. 185. 



Delicate three-sided 
chisel, useful for 
opening cavities on 
approximal sur- 
faces. 



completed will not be noticeable. When the cavity is of larger size and 
the enamel wall on the labial surface has been weakened by caries it will 
have to be removed, and access will thus unavoidably be afforded from 
that side. Whenever possible, however, undue enlargement of the 
cavity and consequent exposure of gold should be avoided. 

In ordinary cavities upon the approximal surface the frail walls 
bordering the orifice should be broken away with 
a small chisel, and after the decay has been removed 
by means of burs or excavators and the proper form 
given to the cavity, the margins should be carefully 
smoothed and bevelled with small plug-finishing burs 
or with the side-cutting edge of the small chisel 
shown in Fig. 166 and here reproduced (Fig. 185). 

Anchorage is obtained in these cavities by slightly 
deepening the cavity at its cervical termination and 
making a shallow undercut in the dentin near the 
incisal border. Retaining grooves should never be 
made in the labial or lingual walls of the cavities, 
as they would seriously weaken them. In approxi- 
mal cavities of large size where they extend from 
near the incisal edge to or beyond the free margins 
of the gum, the difficulties of producing a perfectly formed cavity 
are greatly increased. While affording greater ease of approach on 
account of their size, the cervical border of this class of cavities is 
apt to be less perfectly prepared owing to its obscure location. When 
the cervical border extends beneath the free margin of the gum the latter 
should be pressed and held away during excavating, so that the cervical 
wall may be plainly seen and operated upon throughout its whole 
extent. 

Cutting of the wall should be sufficiently extended rootward to in- 
clude any defects or checks in the enamel bordering it, and should be 
made entirely smooth and free from angles, for it is the most vulnerable 
border of the cavity after the filling has been completed. Should the 
cavity extend to near the enamel termination at the cervix, it will be 
best to still further extend it so as to pass beyond this margin ; for if a 
small portion of enamel be left there it will be liable to be broken 
away in the process of filling and thus seriously impair the junction of 
the filling with the border. 

So, also, if the cavity on account of its size should approach very 
near to the incisal edge, it is best to remove this frail corner and con- 
vert the cavity into a compound one. Where such a weak corner is 
allowed to remain it is very frequently broken away in subsequent mas- 
tication. Such a result is shown in Fig. 186. An accident like this is 







SIMPLE APPROXIMAL CAVITIES. 231 

more likely to occur in thin, fiat teeth where the plates of enamel meet- 
ing at the incisal edge have little or no dentin between them. 

Where doubt exists as to whether the corner should be F lg6 
removed or allowed to remain, it is well, after the cavity has 
been prepared, to test the strength of the corner by strong pres- 
sure upon it in the direction of the long axis of the tooth with 
a piece of orange-wood. If it resists this strain it will prob- straight 
ably resist the force of mastication, and if it break away under fracture - 
the test it will demonstrate that it would have been unwise to allow it 
to remain. 

If the corner be left as a border and support for the filling it should 
not be weakened by a deep retaining groove. Such groove or anchorage 
should be shallow, and as far removed from the incisal border as the 
conditions will permit. 

In many cases, where the incisal wall would be seriously weakened 
by any attempt to use it as an anchorage or support for the 
filling, and where it seems undesirable to remove it, an ex- r^-~* 
cellent anchorage for the lower border of the filling may be *s| 

obtained by cutting an extension upon the lingual surface in y^jK 
the form of an arm, as shown in Fig. 187. 1 Such extension, I 4 
if made but little deeper than the enamel, will not materially Fjf 
weaken the tooth and will secure the filling perfectly. Lingual ex- 

Its position should be near the incisal edge, but not so tension an- 

. , chorage. 

close to it as to weaken the part. 

In the anterior teeth the relative difficulties between mesial and distal 
cavities are insignificant. 

BICUSPIDS AND MOLARS. 

Class H. — The preparation of small cavities on the mesial and 
distal surfaces of the bicuspids and molars, though simple in character, 
is usually most difficult of thorough performance. This is due entirely 
to their inaccessibility when the teeth are closely approximated. How 
to approach these cavities is often a matter of no small concern to the 
student or young practitioner, and the preparation and filling of them 
is generally more difficult than that of larger and more complicated 
cavities in exposed situations. To lessen the difficulty of approach it is 
important, whenever practicable, to create by wedging beforehand as 
great a separation as possible between the teeth. The greater the space 
gained the less the difficulty of approach. 

When conditions will not warrant cuttinp; down to them from the 
occlusal surface, and thus converting them into compound cavities, 
but two ways of approach are left open : one is from the direction of 
1 Dental Review, vol. ix. pp. 812 and 819. 



232 



PREPARATION OF CAVITIES. 



the occlusal surface, and the other from the buccal aspect. Usually the 
former is chosen, as it involves less sacrifice of tooth structure, although 
by it the difficulties are increased owing to the limited space in which 
we are obliged to operate. 

These cavities can usually be best opened and mainly prepared with 
a round bur. After the decay has been removed and the walls defined 
and prepared, the cavity may be made retentive in form by slight under- 
cutting throughout its entire circumference, or it may be enlarged at 
two opposite points only. The cervical wall can be inwardly deepened 
by an obtuse-angle hatchet excavator as illustrated in Fig. 188, and the 
lower or occlusal wall be slightly undercut by an acute-angle excavator 
like Fig. 189. 



Fig. 188. 



Fig. 189. 




T 



Obtuse-angle hatchets. 



Acute-angle hatchets. 



The sharp angles on the cutting edges of these excavators should 
be rounded before being used, so as to avoid the formation of angles in 
the cavity. 

As the enamel rods on this surface radiate outwardly at such an 
angle as to give the proper bevel to the orifice of the cavity, a careful 
following of their lines in the preparation of the cavity margins will 
be all that is necessary to give them the desired form and strength. 

Occasionally these cavities, instead of being round or nearly so, have 
a decided oval or oblong form, their greater diameter being in a bucco- 
lingual direction, in which event the cavity may generally be best ap- 
proached, for preparation and filling, from the buccal aspect. 

When this seems desirable, the cavity should be extended so as to 
open at the approximo-buccal angle. A round bur is best suited for 
this purpose, and when the extension has thus been made the cervical 
and occlusal walls of the cavity may be slightly grooved with a hoe 
excavator and the inner or lingual wall be made abrupt and also slightly 
undercut. 

In all cases where sufficient space cannot be gained to operate satis- 
factorily from the direction of the occlusal surface, an extension of the 
cavity to the buccal aspect is the only alternative. 



COMPOUND CAVITIES. 233 

Where simple cavities upon the approximal surface are large they 
may extend so near to the occlusal surface as to weaken it. When this 
is the case the enamel wall should be cut away and the cavity converted 
into a compound one of the approximo-occlusal type. 

III. Compound Cavities. 

INCISOKS AND CANINES. 

Classes I and J. — Memo-labial and disto-labial cavities occur from 
the near approach or union of simple cavities upon their 
respective surfaces. Cavities of considerable length up- 
on the approximal and labial surfaces are very apt to L | 
join one another by extension of caries. When they JT^I 
do not join they are usually separated by a narrow terri- (fl jf 
tory of more or less impaired tooth tissue, and in such Mesio-iabiai cay- 
cases must be united to obtain a satisfactory result. Each 
cavity should be as nearly prepared as possible separately, after which 
the intervening tissue should be cut away and the lines of the channel 
connecting the two be made as strong and smooth as possible. This 
channel will usually be of less width than either of the cavities, but not 
more difficult to fill on this account. Fig. 190 shows a front view of 
such a compound cavity. 

Whether the cavity be a mesio-labial or a disto-labial one will not 
materially affect the manner or difficulty of operating. 

Classes K and L. — Mesio-lingual and disto-lingual cavities are 
formed in the same manner as those of classes I and J except that in 
these cases the lingual surface is involved instead of the labial. ^ 1Q1 
Extensive caries in the region of the basilar pit or of the 
fissures connected with it often approaches so nearly to an 
approximal cavity in the same tooth as to demand the union 
of the two (see Fig. 191). The method of preparing and 
uniting the two is substantially the same as that followed in 
classes I and J, just described. 

A mesio-lingual cavity is perhaps more easily prepared and filled 
than a mesio-labial one, for in its preparation the free cutting away 
of the intervening wall is permissible, which affords increased room for 
operating. 

Fortunately, a lingual cavity rarely extends so far as to connect with 
both a mesial and a distal cavity. When it does, the joining of the 
three cavities very seriously weakens the crown at the point where the 
greatest strain occurs. 

Classes M and N. — These classes include cavities upon either the 
mesial or distal surfaces connecting with a cavity upon the incisal edge. 




234 PREPARATION OF CAVITIES. 

They usually occur in consequence of the wearing away of the latter 
surface through attrition or from the necessitated removal of the incisal 
corner on account of weakness. Both the approximal and incisal cavi- 
ties may be prepared separately as described in classes F and G, after 
which they should be connected, the walls made strong and smooth and 
properly bevelled. 

A typical cavity of this class is shown in Fig. 192. In all such 

cases the labial plate of enamel should be preserved intact as 

far as possible for appearance sake, and if any cutting has to 

Lwilfl be done to increase the size or depth of the incisal portion of 

1^ I the cavity, it should be done at the expense of the lingual wall. 

wji;)) In order to protect the labial wall from possible fracture in 

mastication the enamel should be bevelled outwardly (as men- 

incisai cav- tioned under class F) so that when filled the gold alone will 

come in contact with the opposing teeth in mastication. 

The only anchorage needed for this class of cavities is a slight 

undercut along the cervical wall and a dovetailed form of the incisal 

portion of the cavity. 

In many cases there is no cavity upon the incisal edge, but where 
opportunity offers for making one (as in the case of thick or worn teeth) 
this method of forming a compound cavity affords the greatest possible 
support and security for a large approximal filling involving the ap- 
proximo-incisal angle. 

Where the crown is thin and unworn upon the incisal surface a com- 
pound cavity of this character cannot be formed, but the same result as 
to anchorage may be obtained by cutting an extension upon the lingual 
surface of suitable size, form, and depth, as described on 
p. 231. One form of such extension where the corner is 
gone is shown in Fig. 187. 1 Another form, represented 
in Fig. 193, 2 consists of giving the extension a curved or 
hooked form. Both forms serve the same purpose, for 
^anlnchorage 6 " they a ff° r( l m these cases perfectly secure anchorage which 
could not be obtained so well in any other way. 
Class 0. — Mesio-disto-incisal Cavities. — Cavities of this character 
differ from the preceding ones principally in extent. The method of 
preparation in each case is similar and the operation requires the 
exercise of great skill and care in order to produce the best results. 
In both cases the following points will have to be observed : 

As the operations are extensive in character, good strong walls are 
needed on all sides to withstand the force exerted in the introduction of 
the filling. 

1 Dental Review, vol. ix. pp. 812 and 819. 

2 I. C. St. John, D. D. S., Dental Cosmos, vol. xxxvi. p. 198. 




COMPOUND CAVITIES. 235 

All margins must be smooth and nicely bevelled. 

No angles or checked enamel must exist along the borders. 

All enamel should be supported by underlying dentin, although 
to avoid the exposure of gold the labial plate (which is thicker than 
the lingual) may sometimes be left thus unsupported for a short distance 
along the approximal and incisal margins. 

No deep anchorages will be required. Only slight ones are needed 
to start the filling at the cervical wall, for the form of the filling, when 
completed, will be such as to afford the greatest possible security. 

BICUSPIDS AND MOLARS. 

Class P. — Mesio-ocdusal cavities in bicuspids and molars represent 
a class not only frequently met with and difficult to fill, but one also in 
which a large proportion of fillings fail. This is largely due to the 
improper shaping of the cavity and the imperfect placing and adaptation 
of the filling. When these cavities are of moderate size, not extending 
as far as the gingival margin on the mesial surface and without any 
great width in a buccal or lingual direction, the preparation and filling 
of them is not attended with any great difficulty ; but where they 
extend beneath the gum margin and are much spread out laterally they 
present complications that are difficult to overcome. 

The cervical margin of such cavities as extend only to or near to 
the free margin of the gum has been aptly styled the "vulnerable 
point/' because when failure occurs in these fillings it usually begins at 
this margin. When, however, the cavity Avail extends beneath the gum 
margin, although the difficulties of operating are increased, recurrence 
of decay is seldom met with, because the conditions favorable to decay 
are not present there. 

In the preparation of these cavities the teeth should have been pre- 
viously wedged in order to afford light and room for excavating, as well 
as for the. subsequent introduction and finishing of the filling. If the 
cavity extend beneath the margin of the gum the latter should be 
pressed away by packing the cavity over-full with gutta-percha for a 
day or two previously. 

After opening and roughly preparing the cavity the rubber dam 
should be adjusted and the cavity thoroughly dried, after which the prep- 
aration can be completed more satisfactorily, as the dryness of the tooth 
will enable the operator to readily distinguish between sound and un- 
sound tissue. 

Whether the cavity be of large or moderate size, simple or difficult 
in character, the niceties of preparation must receive due consideration. 
The cervical portion of the cavity should be dressed until a strong 
sound wall is obtained. In it there must be no angles, and bordering 



236 



PREPARATION OF CAVITIES. 



Fig. 194 




it there must be no decalcified tooth structure and no checks in the 
enamel. Should either of the latter be found, further cutting of the 
wall will be necessary until these defects are entirely obliterated. 

If the cavity should extend rootward to near the termination of 
the enamel, it will be necessary to deepen the cavity so as to include 
this portion, otherwise injury will be liable to result from the fracture 
of this frail section of enamel during filling. 

The outline of the cervical wall may be either distinctly curved or 
more or less flattened ; the latter form, shown in 
Fig. 194, A, being preferred by many on account 
of the assistance it renders in filling. The buc- 
cal and lingual walls must be dressed to a smooth 
outline and bevelled, and where the size of the 
cavity warrants it should be extended so far 
toward the buccal and lingual surfaces as to free them from the danger 
of future decay. In Fig. 195 the dark portion represents the buccal 
aspect of the completed filling. None of these walls should be deeply 
undercut to assist in either the introduction or retention of the filling, 
for such undercutting is a source of weakness, but shallow grooves are 
not objectionable when needed. 

Starting pits or grooves should not be made in the cervical wall 
except in rare cases ; a slight dipping inward of the wall, as indicated 
at a, Fig. 196, being sufficient to furnish all the retentive form needed 
at this part of the cavity. 

That portion of the cavity in the sulcus on the occlusal surface may 
Fig. 196. Fig. 197. 



(After Black.) 





Prepared cavities and anchorages. 

be made retentive either by slightly enlarging it inwardly or by widen- 
ing it at its termination, as shown at A, Fig. 196. Where the occlusal 
and approximal portions of the cavity meet, the angles should be re- 
moved and the cavity well opened so as to afford access and give 
strength to the filling (b, Fig. 197). 

Fig. 198 represents a compound cavity of this class, incorrectly 
formed. In it moderately sharp angles are seen at the points 
where the occlusal and approximal portions of the cavity join. 
In very exceptional cases, cavities upon the approximal sur- 
faces that involve a slight portion of the occlusal do not need 
to be extended along and include the sulcus or sulci on this 
surface, owing to the fact that no fissures and no decay exist in them. 



Fig. 198. 




COMPOUND CAVITIES. 237 

In such instances the occlusal portion of the cavity should have a V 
shape as shown in Fig. 199, and anchorage for the filling at this point 
be obtained by slightly undercutting the approximo-occlusal walls at A 
and B. 

Fig. 200. 






^B B X D 

Prepared cavities and anchorages. 

In the diagram Fig. 200 the black portion represents the floor 
of the cavity ; A and b indicate the points to which the buccal and lin- 
gual walls should be cut ; c and d show the curved form of cavity 
after the occluso-approximal angles have been removed, while the 
curved line outside of the cavity indicates the approximal contour of 
filling, with contact point at h. 

Fig. 201 represents a compound cavity (mesio-occlusal) in a lower 

second molar. These cavities differ from similar ones in _ _ A1 

Fig. 201. 
bicuspids principally in having the occlusal portion of 

the cavity exteud in different directions along the sulci. 

All of the terminations should be well rounded and in 

no portion of the cavity should distinct angles be allowed ^fesio-occiusai cav- 

L J ° ity m lower sec- 

tO remain. ond molar. Pre- 

Class Q. — Disto-occlusal cavities in either the bicus- pared ' 
pids or molars are not essentially different from mesio-occlusal cavities 
in the same teeth. Owing to their position they are more difficult 
of approach, but their manner of preparation and their form are vir- 
tually the same. 

Class R. — Occluso-buccal cavities are more frequently met with 
in the lower than in the upper molars. This is due to the general 
presence of a pit upon the buccal surface in which decay by extension 
reaches so near to the occlusal surface that the occluso- 
buccal wall is weakened and has to be removed. Coin- 
cident with this there is usually a cavity of some size 
upon the occlusal surface, and the union of the two 
cavities becomes necessary to insure a satisfactory 
result in filling them. A common type of such cav- 
ity is Shown in Fig. 202. Occluso-bn17al cay- 

The channel connecting the two cavities is usually ity in lower molar. 
narrower than either of the latter, and also more shallow, 
thus conserving the strength of the tooth. As, however, the strain 
upon the walls bordering this channel is very great in mastication they 




238 



PREPARATION OF CAVITIES. 



Fig. 203. 



should be trimmed until solidity is obtained, and also be considerably 
bevelled for purposes of strength. 

Class 8. — Occluso-lingual cavities in the bicuspids and molars are 
of rare occurrence except in the upper first and second molars, where 
they follow the line of the sulcus extending between the mesio-lingual 
and disto-lingual lobes. Sometimes the cavity is nearly confined to the 
occlusal surface, running over on to the lingual surface but slightly. 
In such cases the cavity is easily prepared by simply cutting the occlusal 
cavity through to the lingual surface, giving the cavity a relatively uni- 
form depth at all points. 

At other times the fissure on the lingual surface will extend farther 
toward the cervical margin, and the cavity when prepared 
will have the form of an L, the longer arm, A, represent- 
ing the occlusal, and the shorter one, B, the lingual por- 
tion of the cavity (see Fig. 203). Where the extent of 
decay does not demand it, it would be a mistake to make 
the floor level of the two portions of the cavity uniform, 
as the extensive removal of sound dentin would greatly 
weaken the disto-occluso-lingual cusp. 
Where extensive decay has already weakened this cusp it is better to 
amputate it below the level of the occlusal plane and extend the filling 
over it. 

Class T. — With the exception of those unusual cavities which 
involve the greater portion of the crown of a tooth, the mesio-disto- 
occlusal cavities in bicuspids and molars are the largest in extent of any 
met with. Being well exposed there is no lack of 
either light or room in which to operate, and the only 
difficulty associated with their preparation and filling 
Jj lies in their size and extent. 

Their preparation is accomplished in the same man- 
ner as those of classes P and §, except that no special 
retentive form need be given to the occlusal portion, 
for with the filling once in place its general form will 
secure it in position. Fig. 204 represents a typical cavity of this class 
in a bicuspid tooth. 




Fig. 204. 




CHAPTER IX. 

EXCLUSION OF MOISTURE— EJECTION OF THE SALIVA- 
APPLICATION OF THE DAM IN SIMPLE CASES, AND 
IN SPECIAL CASES PRESENTING DIFFICULT COMPLI- 
CATIONS—NAPKINS AND OTHER METHODS FOR SECUR- 
ING DRYNESS. 

By Louis Jack, D. D.S. 



The interference of the secretions of the mouth offers a considerable 



obstacle to the treatment of the teeth. In some in- 
stances the flow is naturally excessive, and in all cases 
it is stimulated by the operative procedures. 

An excessive flow of saliva is uncomfortable to the 
patient ; its accumulation also impedes the operation, 
and interferes with the view of parts by refracting 
the rays of light. 

During the preparation of accessible cavities, par- 
ticularly those of the upper front teeth and the occlusal 
surfaces, the accumulation may be carried off by the use 
of a saliva ejector, a simple form of which is shown 
in Fig. 205, which form, or some modification of it, is 



Fig. 206. 



Fig. 205. 




used where a connection can be 
made with the water supply, and 
ordinarily it is used in association 
with the fountain cuspidors. An- 
other form, which is connected 
with a small reservoir of water, 
is shown in Fig. 206. Either 
of these forms has a further use 
for drawing off the saliva in con- 
nection with the employment of 
the rubber dam to lessen the dis- 
comfort of the patient. 

Use op Rubber Dam. 

During the preparation of cavi- 
ties on the approximal surfaces of 
the bicuspids and molars where it is essential to have 



unrestricted 

239 



240 EXCLUSION OF MOISTURE. 

view and the exclusion of blood, the presence of which is inseparable 
from thorough preparation of the cervical margins, it is necessary to 
make use of the rubber dam. When used for this purpose the 
material generally becomes impaired by the action of the instruments 
in their free use at the cervix ; but the economy of time and the essen- 
tials of thorough performance of this class of operations warrant the 
application during this portion of the treatment. 

When the case is ready for the filling process a new piece of the dam 
should be prepared, and adjusted with great care to prevent the ingress 
of the least moisture. Without this appliance the greatest skill is pow- 
erless to secure sound results in large, difficult, or complicated cases. 
The introduction of this invention has made it possible to execute 
with gold, operations which previously were impossible ; not the least 
advantage resulting from its use is that the operator has free use of the 
left hand to assist the right. 

Quality of the Rubber. — The quality of the rubber greatly modi- 
fies the facility of its application. It should be of medium thickness 
and of light color, as it then absorbs less light. It should be freely 
extensible and so elastic that when the thumb is forcibly pressed into it 
it returns to its normal form on the removal of the force. If it re- 
sponds to this test it will not tear if fairly applied. 

The size and form of the piece should be such as to avoid encum- 
bering the face of the patient and to permit the lateral extension to be 
folded out of the way in such manner as to prevent obstruction of the 
view. The form generally best suited is a triangle, which form also 
permits of its most economical use. 

For the front teeth the piece should be moderately small ; for the 
bicuspids and molars the size should be ample and is best adapted when 
cut from strips about seven and a half inches in width. 

The selected piece should have holes cut in it of such size as to 
correspond with the dimensions of the teeth over which it is to pass. 
When more than one hole is required the holes should be at such dis- 
tances apart as will present a sufficient amount of material to allow for 
the take-up in the application, so that the strait which passes between 
the teeth shall be sufficient to allow the edge to be carried upward to 
form a valve at the cervices of both teeth and not be under such strain 
as to interfere with the valvular action of the edges of the rubber. At 
the same time there should be no excess to hamper the view or inter- 
fere with the placement of the filling material. 

Attention to the valvular arrangement of the dam at the cervix will 
avoid subsequent difficulty and will prevent in many instances the 
infliction of pain in using ligatures except upon the tooth under treat- 
ment and the adjacent one. The appearance of this valve is shown in 






USE OF RUBBER DAM. 241 

Fig. 207. Fig. 209. 




perspective by Fig. 208, a, b, c, 
d. The holes iii the rubber may 



Fig. 208. 





a be 

Diagrammatic drawing : form of valve. 

be formed with a punch of suit- 
able size, which should be forced 
upon the end of a close-grained 
piece of hard wood. They may 
be made Avith a little practice 
by drawing the rubber over a 
round-ended instrument with 
some force' and pricking the 
rubber at a suitable point with 
a sharp knife, when a round 
section escapes. The difference 
in size of the holes is deter- 
mined by the distance from the 
end of the instrument at which 
the puncture is made. The deter- 
mination, however, of size and 
distance is not easily made in 

this manner. The best appliance for the purpose is the Ainsworth 
punch (see Fig. 209), with which complete control of size and distance 
may be easily effected. 

16 



The Ainsworth punch. 



242 



EXCLUSION OF MOISTURE. 



The arrangement of the holes in the triangular piece should differ 
for each section of the mouth. 

Fig. 210 shows a piece for the central incisors. The figures repre- 
sent inches. 

Fig. 211 shows the arrangement of holes for the upper bicuspids 
and molars. It will be observed the line of holes is not parallel with 
the upper edge. 



Fig. 210. 



Fig. 211. 



Fig. 212. 




For central incisors. 



For upper bicuspids and 
molars. 



For lower bicuspids and 
molars. 



Fig. 213. 




For lower front teeth. 



Fig. 212 shows the arrangement for the lower bicuspids and molars. 
Here, too, the line of holes is not parallel with the edge, to allow for 
the difference in distance from the commissure of the lips to the ante- 
rior and posterior holes. 

Fig. 213 shows the arrangement when the lower incisors and canines 
are included. Here the line of the apertures 
is curved. 

By conforming to these arrangements of 
the openings in the rubber, and by extend- 
ing the line in conformity with it, as well as 
by increasing the size of the piece, any num- 
ber of holes may be made, to include any 
portion or all of the teeth of one quarter of 
the denture when that may be required. 

The number of apertures in the rubber should be such as to give 
easy access to the operation and to permit the free entrance of light. 
For the anterior teeth five to six holes are necessary, and for the pos- 
terior teeth from four to six as may be needed to secure the above-stated 
objects. In general, at least two teeth anterior to the one operated 
upon, and when admissible the one posterior, should be included. 

The Placement of the Dam. — When the teeth are not in firm con- 
tact or when their attachments are flexible the adjustment of the dam 
is simple. But when the teeth are rigid certain preliminary conditions 
should be secured. It has been pointed out in speaking of the prepara- 
tion of the teeth for a series of operations that they should be well 
cleaned of any deposits which may be upon them and be polished on 
their approximal surfaces. This makes easier the insertion and the 
application of the rubber. 



USE OF RUBBER DAM. 213 

Generally where the case under treatment is an approximal surface 
the necessary preparatory separation makes easy the immediate open- 
ing of any interstices near the operation. In cases of extreme fixa- 
tion of the teeth a piece of rubber dam placed for a day or so in a 
couple of the neighboring spaces makes it easy to enter the margin of 
the interstices. The passage of a silver tape with a little benne oil or 
cosmolin on it often answers as an equivalent means. In the front 
teeth a thin wedge inserted just above a tight point permits an easy 
entrance. 

The preliminary silking of the adjoining spaces, particularly if the 
silk be coated with cosmolin or its equivalent, also facilitates the 
passage of the rubber, and for this purpose soaping the under surface 
of the rubber adjacent to the holes is recommended. 

At first the novice finds difficulty in making application of the dam, 
but practice cultivates facility. In general it is better to commence 
with the anterior hole and proceed posteriorly until all the intended 
teeth are included. Thus for the left lower teeth the rubber is taken 
with the index fingers applied to the upper surface, the other fingers to 
the under surface, and is grasped near the hole for the front bicuspid ; the ' 
hole is extended ; the edge of the rubber is inserted in the mesial inter- 
stice and is carried down to the gum. It is then drawn over the tooth 
and passed into the next interstice in the same manner. This method 
is pursued with each tooth until all are included. The passage of the 
rubber is facilitated by helping it downward by the insertion of floss 
silk, which is held taut, and with a firm and gently sliding movement 
the rubber is conveyed toward the cervix. 

When the most distant tooth is the lower third molar, it is generally 
best when the cavity is on either side of the last interstice to pass the 
jaws of a dam clamp through the posterior hole ; the clamp is then made 
to grasp the tooth, the dam is conveyed to the gum by silking, and the 
adjustment is then carried forward from tooth to tooth. The same pro- 
cedure is sometimes applicable with short third molars in the upper 
denture, or in case any of the posterior teeth are so shaped as not to 
retain the rubber. 

When the rubber is adjusted over the teeth the purpose of the dam 
is effected by directing the edge of the dam under the free margin of 
the gum. This is done by passing a silk thread around the tooth, and 
crossing the ends, when by a drawing movement of the thread it travels 
down the inclined surface of the cervix, carrying the dam with it, thus 
making a more secure formation of the valve. 

This method avoids the needless paining of the patient caused by 
pushing the threads against the gum with instruments. Whenever 
necessary for securement the ligature should be tied. This should be 



244 EXCLUSION OF MOISTURE. 

done to the teeth on both sides of an approximal cavity. It is neces- 
sary here to place the cervical margin of the cavity in full view and to 
make certain the exclusion of moisture, which otherwise might pass the 
valve by capillary attraction. 

The ligature should usually be passed but once around the tooth and 
then be tied with a surgeon's knot, the place of the knot being on the 
outside. When there is much strain the thread may be passed twice 
around the tooth, but this should be avoided as being more painful and 
as increasing the bulk of the ligature. 

To prevent the rubber from displacement by the movement of the 
cheeks on the posterior teeth when they are long, if after drying the 
surface a little sandarac or damar varnish is applied at the last inter- 
stice, the rubber becomes fixed. 

In cavities extending above the cervix where a ligature cannot be 
placed above the cervical border of the cavity, other means have to be 
adopted to obstruct the entrance of fluids. Here the strait of rubber 
between the holes should be much wider than usual ; the abundant fold 
may then be forced beyond this margin with a matrix, when, by drying 
the parts and by the deft introduction of alcohol varnish and suitable 
wedges, dryness of the parts is attained. In the most extreme cases of 
this nature the part beneath the normal gum line may be filled with 
a permanent plastic substance, as described in the section on Lining 
Cavities (see Chapter X., p. 258). 

The Securement of the Dam from Displacement. — When the 
teeth are short from incomplete development or when their form is 
tapering from the gum toward the occlusal aspect there is always ten- 
dency of the rubber to escape, and the contraction of the commissure 
pf the lips tends to the displacement of the dam at the posterior teeth, 
the latter movement often being sufficient to overcome the friction of 
the ligatures. When these difficulties arise a clamp is required. 

The Clamp. — This is an instrument of much value not only as a 
means of securement of the rubber, but as an adjunct to prevent the 

Fig. 214. Fig. 215. 






Dr. Southwick's clamps. Dr. Huey's clamps. 

rubber from obstructing the view. Clamps are more especially needed 
to detain the rubber on the molars and are rarely required for the bicus- 
pids or the anterior teeth, since, if the foregoing directions are followed,, 
the necessity for their use will but seldom be presented. 



USE OF RUBBER DAM. 



245 



Forms of Clamps. — For the molars various sizes and shapes of the 
" Southwick " and of the " Huey wisdom-tooth clamp " are sufficient 
for general use. In addition to these " Palmer's set of eight/' after 
the sharp points of the jaws are rounded, will furnish the requisite 

variety. 

Fig. 216. 




Dr. Delos Palmer's set of eight clamps. 

The Application of the Clamp. — The selected clamp is extended 
by the clamp forceps to enable it to pass over the molar. It is con- 
veyed to the middle portion of the tooth, when the inner beak 
should be brought against the tooth at the gum margin ; then with 
this point as a fulcrum the outer beak is carried to the cervix on the 
buccal surface. Much pain may be avoided in the employment of 
this appliance by deft and careful placement. Injury of the gum and 
needless pain has frequently been inflicted by careless use of force in 
the application of this appliance. Much of this may be avoided by 
the previous ligation of the tooth, which will prevent the tendency of 
the clamp to descend beneath the gum when the necks of the teeth 
are much inclined inward. 

When it is necessary to force the clamp against the soft tissues the 
previous application of a solution of cocain will obtund the tissue and 
render the application tolerable. 

The Arrangement of the Dam on the Face. — This concerns the 
convenience of the operator and the comfort of the patient. To give 
easy access and permit the entrance of light, the rubber is drawn aside 
at each upper corner by dam-holders. The simpler forms of these are 
sufficient and are more convenient than the more complicated ones when 
triangular pieces of rubber are employed. In addition a supporter, 
shown at Fig. 218, passes over the head and engages at each end with 
the holder. The comfort of the patient is secured by including a nap- 
kin along with the rubber in the clasps of the holder. The excess of 
the rubber at each side should be taken up in a fold and secured to the 



246 



EXCLUSION OF MOISTURE. 



napkin by dressing pins. The suspended part of the rubber is kept 
taut by pendent weights. 

The application and arrangement of the dam becomes Fig. 218. 
by practice a very simple matter, and should not be the 
occasion of discomfort or pain to the patient. 

Fig. 217. 






Design of Dr. Cogswell. 



A supporter. 



The Use of Napkins. — There are many instances of simple cases in 
accessible positions not of approximal surfaces, when the general flow 
of saliva can be kept under control by the saliva ejector, when it is not 
necessary to use a rubber dam. Also for children, when the teeth are 
too short to permit the correct application of the dam, it is necessary to 
find other means to control the moisture. Here the reliance is upon 
napkins, and with them much skill may be displayed by deft operators. 
For this purpose the napkin should not be over eight inches square. 
The manner of folding is to carry two adjacent edges to the diagonal 
of the napkin, and then fold again in like manner; by this plan the 
folds are held in place. 

Strips of " birdVeye " linen of various lengths and widths are also 
serviceable for simple cases and for children. 

To apply a napkin to the upper right side, the point is taken between 
the left index-finger and the thumb, the broad end being held at the 
same time by the right hand. The lip near the right commissure is 
everted, the point is inserted here, and by the taut action of the left 
hand the napkin is next laid between the gum and the lip. It is then 
carried backward until it reaches the duct of Steno, when the left index 
finger is applied to maintain the compression at this latter point. The 
free end of the napkin lies upon the lower lip. For the left side the 
action is the same by the reversal of the hands. 

For the lower teeth the application differs by commencing for each 
side at the upper canine of that side. When the duct of Steno is 
reached a fold is made to effect the compression of the orifice of the 
duct, then the napkin is laid between the cheek and the lower teeth 



USE OF RUBBER BAM. 



247 



and kept in position by the left index finger, a mirror, or a cheek- 
holder. 

An important preliminary to the application of a napkin to these 
positions is that the saliva ejector be first placed in action and that the 
surfaces of the gum and cheek be wiped to dryness, to cause the napkin 
to cling to the surface. If the surfaces are covered with mucus and 
at the same time are wetted with saliva, the napkin easily becomes 
displaced. 

For the inner surface of the lower teeth a considerable fold of cot- 
tonoid or similar substance laid beneath the tongue materially prevents 
access of saliva here, and also, by preventing the contact of the tongue 
with the teeth, lessens the opportunity for the access of moisture by 
capillary attraction between the tongue and the teeth under treatment. 
In instances where the form of the parts permits, the fold of cottonoid or 
of linen may be retained in place by a dam 
clamp upon any adjacent posterior tooth. 

For the medication of cavities where it is 
important to confine the remedy to the 
tooth ; in short operations, such as temporary 
stoppings, and particularly for the simpler 



Fig. 219. 



Fig. 220. 





The Denham shield. 



Shield in use. 



cases of children, the Denham coffer-dam shields shown in Fi^s. 219, 
220 are of much advantage, more particularly for the lower teeth. 
With these the ejector forms a valuable aid. 



NAUSEA. 

The contact of rubber dam with the tongue and the contiguous parts, 
the presence of napkins, and the touch of the fingers to the oral surfaces 
frequently excites nausea. With some persons this kind of distress is 
extreme and produces simulation of faintness and nervousness. This 
condition may generally be relieved by the use of aqua camphora, a few 
drachms being used as a gargle to the mouth and the throat. When 
indications of faintness appear a drachm may be swallowed with imme- 
diate benefit. 

In case excessive nausea is occasioned by the contact of the appli- 



248 EXCLUSION OF MOISTURE. 

ances with the tongue or palate, these surfaces may be painted with 
tincture of camphor. Spasmodic coughing, not infrequent with nervous 
persons, yields to the same treatment. Camphor appears to relieve in 
these instances by its antispasmodic power, and it is stated to have also 
a specific action upon the eighth pair of nerves. 

Nervousness coming on during any of the operations upon the teeth 
may as easily and in the same manner be avoided. It will be observed 
that in neither of these conditions are the first signs of approaching 
syncope apparent, viz. sighing respiration, pallor, and clammy perspi- 
ration of the face. 

A condition somewhat simulating approaching syncope sometimes 
appears in connection with the use of the rubber dam, due to partially 
suspended respiration, which is caused not so much by the obstruction 
of the mouth as by the unpleasant sensations occasioned by the appli- 
cation and presence of the dam. This may at once be overcome by 
requesting the patient to breathe deeply through the nose. 



CHAPTER X. 

THE SELECTION OF FILLING MATERIALS WITH REFER- 
ENCE TO CHARACTER OF TOOTH STRUCTURE, VARIOUS 
ORAL CONDITIONS AND LOCATION, DEPTH OF CAVITY 
AND PROXIMITY OF THE PULP— CAVITY LINING, WITH 
ITS PURPOSES. 

By Louis Jack, D. D. S. 



The general object in view in the filling of a prepared cavity is to 
secure the future preservation of the tooth at that part from the recur- 
rence of caries. This involves a consideration of the character of the 
material to be used, in relation to its adaptability to the conditions of 
age, the quality of the teeth, and the oral conditions which for the time 
are an expression of the general state of the organism. The habits of 
the patient as to general care of the teeth also have some bearing upon 
the probability of permanence of the reparative operation. A material 
adapted to preserve the teeth when they are of resistant quality and 
when the general health is sound and the care good, may be out of 
place when the opposite conditions exist. Methods of procedure have 
some bearing upon the result, and the influence of these has also to be 
kept in view. 

The general characteristics of the material to be used as a pre- 
servative of tooth structure are of importance in the following order : 

Resistance to chemical action ; 

Capability of adaptation to the surface of the cavity ; 

Sufficient hardness to withstand the force of mastication and the con- 
sequent attrition. 

Capability of form and smoothness are also important in relation to 
cleanliness, which more than any other indirect influence has the greatest 
bearing upon the preservation of the margins from subsequent softening, 
as will further appear. 

The Materials. 

The various accepted materials in use are : gold, tin, amalgams, the 
basic oxid cements, gutta-percha. 

The first three named may be designated as permanent in their cha- 

249 



250 FILLING MATERIALS. 

racter, and the others as of a temporary nature, which, after fulfilling- 
important uses in this way, are often preparatory to later and permanent 
treatment. 

Gold. — The properties of gold which adapt it for the restoration of 
carious teeth are its pliability and softness, which permit its adaptation 
to the form of the cavity ; its tenacity, which gives facility of introduc- 
tion and consolidation ; and its agreeableness of color, which, when the 
surface is solid, smooth, and unburnished, approaches more nearly the 
shade of the teeth than any other metal. 

Notwithstanding these appropriate qualities the packing of gold 
requires the employment of considerable force to overcome various 
resistances to its adaptation and solid condensation. To effect the 
requisite degree of density percussive force frequently becomes necessary. 
The effect of percussive force, if employed throughout, is liable to be 
expended on the margin toward which it is directed, and while this may 
not inflict any injury upon the borders of cavities when the dentin and 
enamel are dense, it often proves injurious to teeth when the anatomical 
elements of the structure are not homogeneous and resistant. 

While it may be stated with the strongest assurance that gold pos- 
sesses the highest preservative qualities and promises greater durabil- 
ity and more satisfactory results than any other material, conditions 
are often presented when to persist in its use would lead to unsatis- 
factory results ; thus, in the approximal cavities of the teeth of children, 
when the calcifying process has not become complete and when by the 
use of the required force some impairment of the incomplete tissues is 
almost certain to ensue. The same maladaptability occurs later in life 
when senile conditions have set in, when the teeth not only have lost 
their density from the peculiar molecular changes which take place 
in the dentin and enamel, but when usually also their resistance to 
chemical influences is greatly impaired. These conditions, coupled with 
the usual inability to properly care for the teeth, render the use of gold 
very questionable. 

Similar states of the dental tissues take place in middle life in both 
sexes, but more particularly in women during the pregnant state, 
when the teeth lose their resistant power, which may later be restored. 
While this condition lasts, materials requiring less force should be 
selected until restoration of resistance has occurred. 

The mode of effecting percussion should be taken into account in 
estimating the influences which bear against the use of gold. When 
percussion is effected by the electro-magnetic instruments with proper 
precautions with respect to the placement of the first portions of gold, 
there is less danger of marginal injury than when percussion is made 
with the hand or the automatic mallet. 



GOLD— TIN. 251 

Finally, the fact must also be recognized that in cases in which the 
character of the structure of the teeth raises a question as to the adapt- 
ability of gold, the physical and nervous resistance of the patient is 
generally below that which would enable him to endure the ordeal 
connected with the thorough completion of the work in harmony with 
the high standard impressed by the continued advancement which has 
taken place in dentistry. 

The tendency to caries of the teeth is a general consideration to 
be held in view in determining the propriety of employing gold. 
When the enamel is hard, the dentin solid, and the general tone of 
the health excellent, there can be no doubt that the inherent qualities 
of gold constitute it the most nearly permanent material. When, on 
the contrary, the opposite conditions exist, gold becomes, in propor- 
tion to the prominence of the unfavorable states present, the most 
questionable material. 

No correct conclusion, however, can be reached without consideration 
of the state of the oral secretions and of the habits of the patient as 
to the care taken of the mouth. The first stage of decay of the teeth 
is the softening of the enamel, which is brought about as the conse- 
quence of the presence of carbohydrates undergoing fermentation in 
secluded positions, which effects the solution of the enamel at these 
places and prepares the way for the occurrence of caries of the dentin. 
Hence a correct hygienic condition of the mouth is the most important 
requirement for the protection of the margins of the tooth adjacent to 
fillings intended to restore them. 

The reaction of the oral secretions in their bearing upon the permanence 
of dental operations has also much weight, since, when these secretions 
have an acid reaction, as the consequence of the presence of fermenting 
material, this condition favors the continuance of the process. A con- 
tinual acid state of the oral fluids, as a consequence of derangements of 
health such as occur in impaired digestion or attend the rheumatic 
diathesis, should be taken into account. Only an appreciable degree 
of alkalinity can inhibit enamel solution unless the general and local 
hygienic conditions are favorable. 

Tin. — This metal, in the form of foil, shavings, and rolled into 
thin strips, while not in much use, should have a wider field than is 
accorded it. It possesses great softness, when chemically pure, and 
is readily adapted to the walls of cavities for the reason that it pre- 
sents less resistance since it does not harden under the mechanical force 
employed. For the same reason, when the cavity is overfilled, the con- 
densing appliances effect by the lateral movement of the mass a better 
and more easily procured adaptation with the cavity walls. For these 
reasons it possesses excellent preservative qualities. 



252 FILLING MATERIALS. 

Tin is also a poorer thermal conductor than gold, and this is an 
important consideration when thermal irritation is to be avoided, and is 
of great value in deep cavities approaching dangerously near to the pulp. 

The objections to this metal are its color when exposed to view and 
its softness, which greatly lessens its value in positions where it may be 
subject to severe attrition. 

Its most important use is for the temporary teeth of children, where 
it may be easily inserted and readily condensed, and rapid progress in 
its introduction may be made, producing good results. 

Except Avhen freshly prepared, tin is not cohesive, a quality which 
cannot be restored by heat, as may be done with gold. 

AMALGAMS. 

Their Composition. — The essential metals which enter into the com- 
position of the dental amalgams are silver, tin, and mercury. To 
these are added various metals in varying proportions to modify the 
" setting," the color, and the affinity for sulfur compounds. For these 
purposes gold is used to influence the rate of chemical combination, and 
it also affects the color. Zinc and copper are added in order to modify 
the shade and also to lessen the affinity for sulfur. 

The effect of various proportions of the metals entering into the 
formulas upon the working qualities of an amalgam is extremely puz- 
zling ; slight differences in proportions causing widely varying results. 

The order in which the metals are introduced into the crucible and 
the degree of heat to which the mass is subjected in the fusing process 
also affect the working qualities. 

The Proportion of the Ingredients. — Valuable tables have been given 
by Dr. Black which indicate that a nearly definite ratio between the 
silver and tin should be maintained. This ratio is found to be approxi- 
mately as follows — Silver 65, Tin 35 — when only these two metals are 
used to make the alloy. Whatever addition of a modifying metal is 
introduced should be of small quantity and at an equivalent reduction 
of the percentage of the tin. 

The ingot of the alloy should be finely divided either by filing or by 
thin shavings made by turning them off in a lathe. When the commi- 
nution of the alloy is made immediately -before using, amalgamation is 
more easily effected than when the filings are kept for any considerable 
time, unless in the latter case there is a disproportion of tin or gold. 
This has been attributed to oxidation of the particles taking place, which 
w T ould retard the amalgamation. Silver not being an oxidizable metal 
under ordinary conditions, the cause of the tardy combination with 
mercury is to be found in the attachment of sulfids to the surface, and 
also to the influences of occluded gases, which also tend to retard 



AMALGAMS. 253 

amalgamation. It is a notable fact that while freshly comminuted alloy 
will more readily amalgamate, it requires more mercury than aged 
alloy. 

More recent investigations by Dr. Black tend to the conclusion that 
the difference in capacity for mercury observed in freshly cut alloy and 
that which has been cut for some time is due to the difference in molec- 
ular arrangement of the alloy, brought about by the comminuting pro- 
cess, which has the effect of hardening the grains and condensing their 
texture in the same manner that hammering the ingot would harden the 
entire mass. By the application of sufficient heat the particles of alloy 
may be " aged " artificially, and this aging is presumed to be simply an 
annealing process. The capacity of the aged alloy for mercury is 
markedly different from that of the freshly cut alloy, as are also the 
working qualities of the resulting amalgam mass, the aged alloy form- 
ing a slower setting and much smoother working amalgam than that 
made from freshly cut alloy. For the further details of this subject 
see Chapter XIII., on Plastic Fillings. 

It is held by many that the proportion of mercury should be in some 
excess, to give decided plasticity to the mass for the purpose of securing 
complete amalgamation of the particles of the alloy. When the amal- 
gamation is complete the redundance is forced out through chamois 
skin, or the mass is kneaded in a napkin or piece of China silk, which 
forces through the meshes most of the excess. It is claimed that this 
method of conducting the amalgamation effects an approximately cor- 
rect atomic relation of the metals with each other; it being held that 
the freer proportion of mercury during the mixing process tends to this 
result, as the redundant metal is carried out with the excess of mercury 
as it is expressed. On the other hand, it is maintained that the propor- 
tions of any given alloy and mercury which will produce an amalgam 
fulfilling every requirement should be established by experimentation, 
and thereafter be weighed out in those proportions. 

The Distinguishing Features of a Good Amalgam. — An amalgam (1) 
Should be non-shrinking ; (2) Should have edge strength ; (3) Should 
maintain lightness of color under the varying oral conditions ; (4) Should 
tend to assume a spheroidal surface. A further qualification is that the 
surfaces of the material may not undergo electrolysis. 

Indisposition to shrinkage is secured by a close conformity of the 
alloy with the proportions above given. 

Edge strength is a term which has not as yet had a clear defini- 
tion in respect to the causes which determine the deficiency of this 
quality. The maintenance of unchangeability of the surface is directly 
related to this important desideratum, as roughening and erosion of the 
margins is the result of molecular waste, which causes a ragged and 



254 FILLING MATERIALS. 

unclean appearance of the edges and an apparent separation of the fill- 
ing from the borders of the cavity. The causes which produce this 
condition are slowly progressive and are continuous. 

This kind of erosion is most marked when contraction takes place, 
from incorrect preparation or improper ratio of the metals entering 
into the formula, or careless manipulation, when capillary defects are 
liable to occur at the margins. 

The most probable hypothesis to account for these observed 
changes is that the presence of moisture having acid reaction, by 
inducing electrolytic action between the metals, brings about the erosion 
of the material immediately within the margins. In these cases the 
exposed surfaces generally suffer little waste, for the reason that they 
are subject to the continued movement of the oral fluids, but it is often 
observed that entire fillings undergo a similar gradual loss and disappear. 
This result is common where there is an excess of gold or mercury. In 
some instances the above described action takes place to a limited degree 
upon the whole surface in proximity with the dentin, when a residue 
is found upon the filling as well as on the surface of the dentin. 

The conclusion from these observed facts is that the securement of 
edge strength depends upon an approximation to the chemical ratio of the 
elements of the alloy. This would appear to be most nearly secured 
when the material is subject neither to shrinkage nor expansion. Expan- 
sion under some circumstances might produce marginal space and there- 
fore lead to the same result ; for instance, if in approximal or buccal 
cavities the depth were greater at one division than another the expan- 
sion of the thicker part of the filling would tend to raise the edge sur- 
rounding the shallow part of the cavity, and would then subject the 
, edge of the filling to electrolytic changes. 

A related condition sometimes appears when an amalgam filling, 
quite hard at completion, after some years becomes comparatively soft, 
which apparently is due to molecular changes. 

The close conformity of the alloy to the proportions recently estab- 
lished by Black, and foreshadowed by the much earlier experimentation 
of Flagg, furnishes a result that is directly conducive to fixity of form 
and edge strength when the margins of the cavity are overlapped. 

This formula is approximately — silver, 68 ; tin, 26 ; copper, 5 ; 
zinc, 1. 

The maintenance of size, form, and strength depends largely, if 
not entirely, upon the influence of silver. When the proportion of 
this element becomes less than 60 per cent, of the formula, the tendency 
to shrinkage appears and holds a nearly direct relation with the diminu- 
tion. When the ratio of silver advances above 70 per cent, the expan- 
sion becomes marked, and at 80 per cent, is excessive. 



THE MINERAL CEMENTS. 255 

Lightness of Color. — The means by which this property may be 
secured have not as yet been well determined and should be the sub- 
ject of extended experimentation. Some of the so-called white alloys 
approximate stability in this respect, but the ratios of the modifying 
metal have not been accurately determined. 

Amalgam as a filling material is adapted to large cavities in the pos- 
terior teeth when the margins are too frail to permit gold to be con- 
densed ; for positions where mechanical force cannot be exerted with 
efficiency, notably the cavities of the third molar ; distal cavities of the 
second molar when of large size ; and the lingual cavities of the lower 
molars. When the teeth are of deficient resistance and when the con- 
dition of the oral secretions favors the rapid progress of caries these 
limitations may be extended to cavities where otherwise gold would 
appear to be a more suitable material. 

As a material for the filling of the deciduous teeth amalgam possesses 
superiority over any other substance, for the reasons that it can be intro- 
duced with less effort than tin and has greater durability than either 
the mineral cements or gutta-percha preparations ; the exception to its 
use here being when the conditions prevent retentive formation of the 
cavity. 

Concerning the form of the cavity adapted to amalgam, it is necessary 
that the retentive formation be equally exact as for gold, since many 
of the formulas in use undergo slight movement for some time after 
their introduction, during which there is liability of marginal displace- 
ment which may lead to the defects treated of under the section con- 
cerning " edge strength." Amalgam, while presenting in its appear- 
ance an unfavorable comparison with gold, is capable of rendering 
important service when every consideration is given to the require- 
ments governing its successful employment. 

To attain the best results in the use of the amalgams requires 
extreme exactness as to the ratios of the ingredients and great care in 
all the procedures connected with the formation of the cavity, the form 
of the filling, and the subsequent finishing process. 

The disqualifications of amalgam are its unsatisfactory color and the 
unknown character of the composition of the formulas as furnished by 
the depots of supply. 

THE MINERAL CEMENTS. 

Oxychlorid of Zinc. — This material, because of its lacking the 
quality of indestructibility, is contraindicated in all exposed situa- 
tions. It possesses, however, a considerable degree of antiseptic power, 
and for this reason renders valuable service in deep cavities not nearly 
approaching the pulp, or even here when the pulp wall of the cavity 



256 FILLING MATERIALS. 

has been previously protected by a layer of gutta-percha or a disk of 
asbestos paper. In such cases, particularly on occlusal aspects, the 
cavity may be nearly filled, leaving a remainder the thickness of enamel 
to be completed with gold. 

For the filling of root canals and pulp chambers it offers the best 
solution of the problem of preventing septic changes in the devitalized 
dentin. After many years, fillings of root canals and pulp chambers 
of this material remain unchanged and are found clean and without 
odor on removal — a result that is not presented by any other filling 
material which may be introduced in these situations. Here it is im- 
portant that the material be not mixed very thin, especially on account 
of the danger of forcing it through the apical foramen. 

A further use of this substance is to influence the shade of devital- 
ized teeth by the color tone it imparts to the crown of the tooth on 
account of its whiteness. This is enhanced by the fact that it comes 
into exact contact and remains without change, a quality which cannot 
be given to gutta-percha or other cements. 

As a temporary filling to correct extreme sensitivity of dentin in 
situations or under conditions which forbid ordinary therapeutic treat- 
ment, oxychlorid of zinc has considerable value. Here when the pulp 
is not closely approached it may be retained for several months with 
considerable advantage. To secure the best results the proportion of 
zinc chlorid should be slightly greater than in the formulas used for 
ordinary fillings. 

Zinc Phosphate. — This material, because of its greater power to 
withstand the influence of the oral secretions, has a wider use than the 
previously described cement. It cannot, however, be depended upon 
/or permanent uses. While in some instances it may remain for several 
years when the oral fluids are neutral and when every attention is given 
toward the attainment of cleanliness, it is nevertheless a deceptive sub- 
stance, since it is liable under temporary changes of the secretions to 
undergo solution, more particularly in situations near the gum. When 
placed in approximal cavities it is extremely liable to become fissured 
at the cervical margin and then permit carious action insidiously to 
take place. 

Unlike oxychlorid of zinc, the phosphate has no antiseptic influence, 
hence it does not inhibit decay of the dentin in its proximity. Its chief 
use is as a temporary expedient for filling cavities on labial and buccal 
surfaces, where, being under easy observation, it may be used with 
benefit. On account of its chemical solution by the oral secretions, 
however slow this may be, it requires frequent renewal. 

Zinc phosphate is also of value for filling the principal portion of 
large compound cavities where the teeth would be injured by the force 



CAVITY LINING IN RESPECT TO PROXIMITY OF THE PULP. 257 

employed in the condensation of gold, and as a desideratum to avoid 
the great amount of time required to fill large cavities with this metal. 
It also here imparts in some instances much strength to frail margins. 

In the cavities which early form upon the occlusal surfaces of the 
permanent molar teeth of children it is of great value, as here it is kept 
clean by the friction of mastication, and being under easy observation 
can be renewed when this is required. When the child reaches the age 
to have permanent operations the margins may be shaped for the reten- 
tion of gold, and in this case the principal part of the cement should 
be allowed to remain. 

Zinc phosphate is of questionable use in pulp chambers as not hav- 
ing antiseptic properties, and being porous it becomes after several 
years quite offensive. For the same reason it is inadmissible for canal 
fillings. Furthermore, for this purpose it is questionable, on account 
of its adhesiveness, whether it is capable of being thoroughly introduced 
into root canals. All things considered, it is for these purposes greatly 
inferior to oxychlorid of zinc. 

Gutta-percha. — Compounds of gutta-percha with oxid of zinc form 
a useful substance for temporary fillings, acceptable for teeth of low 
grade at points not subject to attrition. Its preservative properties are 
very considerable, and were it not subject to surface degeneration would 
in the situations noted be a nearly permanent material. 

The requirements for its successful use are that it be not heated 
higher than 212° F., that the cavity be quite dry, that it be intro- 
duced in small pieces, and be kept under continual condensation until 
cooled to prevent shrinkage. (See Chapter XIII.) 

Cavity Lining in Respect to Proximity of the Pulp. 

As caries approaches the pulp it reaches a period when the proximity 
of this organ is so close as to require much care to avoid irritation and 
probable congestion. Under these circumstances it is necessary to 
avoid thermal conduction and to exclude chemical influences. After 
disinfection of the dentin some substance the ingrediency of which 
is non-irritating and non-conducting should be selected to overlay the 
pulp wall of the cavity. Here choice must be made between gutta- 
percha and either of the classes of mineral cements. 

When the use of gold is preferable for the external portion of the 
filling, it is required that the foundation be sufficiently solid to with- 
stand the force to be applied to the gold. Hence one of the cements is 
here necessary. Previous to the placement of the cement, should the 
pulp be near, the surface should be covered with a thin solution of one 
of the resins to prevent the influence of the fluid element of the cement 
from producing irritation. Copal ether varnish, a solution of hard 



258 FILLING MATERIALS. 

Canada balsam in chloroform, or the solution of nitro-cellulose in 
amyl acetate sold as " kristaline " or "cavitine" are effective 
materials for this purpose. When the cavity is deep the layer of 
cement should be brought to the inner line of the retentive grooves. 
As soon as hardening takes place the metallic covering may be given. 

When the shallowness of the cavity will not permit a considerable 
layer of the cement, a metal cap covering the pulp wall of the cavity 
filled with the cement may be laid in place, the metal of the cap thus 
sustaining the force. 

These forms of cavity lining are of great utility, and should be 
regarded as of importance. 

Marginal Cavity Lining. — When cavities are situated on approxi- 
mal surfaces of the teeth and extend high up on the cervical aspect so 
as to place them beyond the probability of efficient service with metal 
foils, and when the lateral walls of cavities are weak either by their 
thinness or by instability from defects of structure, some form of 
" lining " is necessary. In the one case, to ensure certainty of per- 
formance at the cervix ; in the other, to prevent injury. 

For the cervical part the choice is between (1) tin, (2) a combination 
of tin and gold, and (3) amalgam. 

Tin has the objection when superimposed above gold that it suffers 
waste, in most instances by electrolysis, to which the mixture of tin and 
gold is not liable. This latter combination — made by folding a layer 
of the tin within the gold foil — appears to give the tin protection. This 
combination is more plastic and more yielding than gold alone, and 
permits adaptation and consolidation in places difficult of approach. 
When used in connection with a matrix thorough consolidation may 
be effected without injury to the cervical margin when the tissues are 
not dense. 

When the color of a lining at the cervix will not be objectionable, 
a quick-setting amalgam answers extremely well, and may at the same 
sitting be followed by the completion of the operation with gold. In this 
situation, whatever the lining material, close conformity with the lines 
of the cervical form of the tooth must be assured. In many instances 
the lining and the completion of this portion of the filling should be 
effected before the rubber dam is placed, when the lining portion is for 
the time being considered in its relations as a part of the tooth. 

When it is necessary to use the mineral cements on approximal sur- 
faces of the posterior teeth for temporary purposes, the cervical border 
should be covered with a line of gutta-percha stopping, to protect this 
vulnerable part of such fillings from the exposure of this border by 
the solution to which they are there liable. 

Lining" Lateral Walls. — For this purpose choice should be made of 



CAVITY LINING IN RESPECT TO PROXIMITY OF THE PULP. 259 

zinc phosphate, since it has the required strength and enters into the 
necessary adhesive union with the margins to give the required secur- 
ity. The layer should be kept within the extreme outer border of the 
cavity, to permit the metal filling to overlay the margin of the enamel. 
When the cavity is deep the retaining groove may be formed in the 
cement. 

A general summary of cavity lining is, that this procedure is required 
in proportion to the difficulty of effective approach, and for the safe 
treatment of teeth below the average of structural quality. 



CHAPTER XI. 

TREATMENT OF FILLINGS WITH RESPECT TO CONTOUR, 
AND THE RELATION OF CONTOUR TO PRESERVATION 
OF THE INTEGRITY OF APPROXIMAL SURFACES. 

By S. H. Guilford, D. D. S., Ph. D. 



The treatment of a cavity of decay by filling must have a twofold 
object in order to subserve its best purposes : first, the restoration of 
the affected part to a healthy condition ; and second, the prevention as 
far as possible of a recurrence of the lesion. 

The first is accomplished by the removal of all disintegrated tissue 
and the perfect filling of the cavity with a suitable and durable material. 
The second demands for its success a proper understanding of the cha- 
racter of the surfaces operated upon and their mechanical and physio- 
logical relations. While the simple filling of a cavity, if properly 
done, will generally prevent the extension of decay on exposed surfaces, 
the same operation on surfaces less favorably situated may utterly fail 
to subserve the desired end. 

The contiguity of the approximal surfaces of teeth greatly favors 
the retention of food and the harboring of micro-organisms, while at 
the same time it prevents the free cleansing movement of saliva be- 
tween them. For these reasons such surfaces, though originally per- 
fect in their continuity, are attacked by caries more frequently than any 
others, except the occlusal surfaces where continuity is broken by fis- 
sures and pits. When once affected by caries, their restoration by fill- 
ing is difficult owing to their inaccessibility, and while the operations 
on this account often lack the perfection that would otherwise be secured 
and the fillings consequently fail, the recurrence of decay is more largely 
due to the same influences that brought about the initial lesion. 

This being the case it is obvious that the original conditions must be 
changed if immunity from future decay is to be expected. This 
principle was early recognized and the first attempt to alter the con- 
ditions was by filing or cutting the approximal surfaces so as to free 
them from contact, on the principle of " no contact, no decay." Where 
all of the teeth were thus separated immunity from decay was generally 
secured, although at the cost of great loss of masticating surface, much 

261 



262 THE SELF-CLEANSING SPACE. 

disfigurement, and subsequent serious injury to the gum and peri- 
cementum. 

Where only an occasional space of this character was made, the 
operation proved a failure because in a short time, through the pressure 
of adjoining teeth and altered occlusion, the mutilated teeth would again 
be brought into contact and the opportunity for decay be increased a 
hundredfold. With the recurrence of decay, cutting or filing would 
again have to be resorted to until but little of the teeth remained, and 
they were eventually lost. On account of its unfortunate results the 
method was for a time abandoned, but in 1870 it was revived in a 
modified form through the teachings and writings of Dr. Robert 
Arthur. His method consisted in altering the form of the approximal 
surfaces of teeth by filing or grinding so as to change the point of ap- 
proximal contact from near the occlusal surface to near the cervical 
margin. This not only changed the normally convex approximal sur- 
face into a flat or plane one, but was also supposed to free it from further 
liability to decay by preventing the retention of food debris and render- 
ing the surfaces and spaces " self-cleansing." The method was measur- 
ably adopted by numbers of conscientious practitioners as a means of 
obviating a difficulty hitherto unsuccessfully combated. In a short 
time, however, it was discovered that its promise of success was not 
being realized, and it was also gradually abandoned. Its failure was 
due to its being wrong in principle, for, while it seemed to offer tem- 
porary relief, its after results were most disastrous. 

By leaving a shoulder near the cervical margin the point of contact 
was simply transferred from one point to another with the result that 
the latter point was far more liable to caries than the former one, owing 
, to its position. More than this, the exposed dentin on the cut surfaces, 
lacking the natural protection of the enamel covering, was apt to be 
sensitive, and the food crowding into the space and pressing upon the 
gum rendered it hypersensitive and eventually caused its recession. 
The discomfort following this unnatural operation, together with the 
increased liability to decay resulting from it, were sufficient to condemn 
the method and cause its abandonment. 

These failures to secure freedom from decay by an unnatural altera- 
tion of the forms of approximal surfaces led to a more careful investi- 
gation of the causes responsible for its recurrence on these surfaces, and 
the gradual adoption of more rational and scientific methods for its pre- 
vention. It was apparent to even the most casual student of compara- 
tive dental anatomy that the number and kinds of teeth found in the 
jaws of man, their arrangement in the arches, and their general form 
were all such as to best subserve the wants and needs of the individual, 
but the more minute points of their external anatomy, their inter- 



NORMAL CONTOUR IN RELATION TO CARIES. 263 

dependence and relation to one another, and the part played by the fluids 
of the mouth in the causation of caries under both original and changed 
conditions, had not previously been carefully inquired into. Under the old 
belief that contact caused decay it was thought that decay upon approxi- 
mal surfaces always began at the point of contact and that this was due 
to the fermentative changes occurring in food debris retained at this 
point. Investigation proved, however, that the points of contact be- 
tween teeth were not only free from decay, but more or less polished 
from slight motion of the teeth in their sockets, and that approximal 
decay always began just above the contact point, that is, slightly nearer 
the gum ; also that it could occur nearly as readily without the presence 
of food as with it. 

It was further noted that the normal contact of teeth on their 
approximal surfaces, which was formerly supposed to be essential only 
for mutual support, was equally necessary for the protection of the 
tender gum tissue from injurious pressure of food in mastication. 

Finally it was observed that those portions of the crown of a tooth 
that were beneath the gum margin or those above it that were constantly 
covered by saliva (as on the approximal surfaces near the gum) were 
always free from the beginnings of decay, and that the approximal and 
buccal or lingual surfaces, when faultless in structure, were first attacked 
by caries on a line corresponding with the point to which the fluids of 
the mouth usually rose. An explanation of this peculiarity was soon 
found in the fact that the saliva is usually alkaline and consequently 
protective of the parts covered by it, but at its surface, in a state of 
rest (as in sleep), this condition of alkalinity is changed to one of 
acidity — the calcium salts are dissolved and decay is begun. 

As a result of the foregoing observations and investigations it 
became apparent to the mass of conscientious workers in the field of 
operative dentistry : 1st. That the natural form or outline of each tooth 
was the best for its particular function, and that to materially alter it was 
to lessen its usefulness and hasten its loss. 2d. That contact of ad- 
joining teeth was essential both to the comfort of the individual and 
the durability of the organs. 3d. That inasmuch as the teeth originally 
decay in spite of their natural form and contact, some plan would have 
to be devised by which, in their repair after decay, liability to a recur- 
rence of caries Avould be greatly lessened if not entirely prevented. 

To fulfill these requirements there was but one course left to pursue, 
namely, to fill approximal cavities in such a way as to restore the 
original contour of the surface, and, in all cases where the extent of 
decay was sufficient to warrant it, to extend the cavities so far over upon 
the buccal and lingual surfaces as to bring the enamel margins within 
the range of protective influences. 



264 



CAPILLARITY OF APPROXIMAL SURFACES. 



The rationale of original and recurring decay upon approximal 
surfaces is readily made apparent by considering certain facts and prin- 
ciples of physics. 

When a tube is inserted in a liquid capable of wetting its surface 
the liquid will rise to a higher level within the tube than the surface 
level of the surrounding liquid. This phenomenon is known as capil- 
lary attraction, and is explained upon the principle of " surface tension 
of liquids." If, instead of a tube, two rounded or flat plates are im- 
mersed in the liquid, the same rising of the fluid between them will 
be noticed. The smaller the tube, or the nearer the two plates are 
together, the higher will the liquid rise. 

Applying the principles governing these facts to the teeth and con- 
sidering them as bodies immersed in a liquid (saliva), it will readily be 
seen that if the approximal surfaces of the teeth were parallel and 
close together the saliva would rise to a higher level between them and 
cover more tooth surface than if they stood farther apart, and being re- 
tained in this narrow space with little opportunity for motion the saliva 
would soon assume an acid character and destruction of the tooth tissue 
begin. This is exactly what takes place upon approximal surfaces 
made flat by filing, and will occur whether fillings have been placed 
in such surfaces or not. 

Normally, however, the crowns of the human teeth are more or less 
convex upon their approximal surfaces and touch each other only at the 
point of their greatest transverse diameters, which is near to and just 
above the occlusal surface. From this point their diameters gradually 
become less until they reach the cervical border, where they are smallest. 
This leaves a triangular interdental space with the base of the tri- 
angle at the gum, as shown in Fig. 221, in which the saliva will rise but 
a short distance owing to the separation near the 
gum and the consequent lessening of the capil- 
lary attraction. For this reason teeth preserving 
their normal forms are less liable to approximal 
decay than they could possibly be under any 
other conditions. 

The earliest treatment of approximal sur- 
faces with a view to the prevention of caries consists in gaining access 
to them by wedging, and if found to be superficially affected by caries 
the removal of the injured structure and the perfect polishing of the 
surfaces. 

When cavities of moderate size are discovered they should be care- 
fully prepared and filled, preserving the original contour as far as 
possible. Decay may recur, but it is less likely to do so with advan- 
cing age, increased density of tissue, and proper prophylactic treatment. 



Fig. 221. 




Showing normal contact of 
teeth. 



CONTOURING AS A PROTECTIVE MEASURE. 265 

Where the decay is of larger extent, however, we have it in our power 
to make such physical change in the parts affected as to render future 
immunity from decay reasonably certain. 

First, it is necessary to separate the teeth well by wedging, to so 
enlarge the cavities as to bring their lateral margins well out upon the 
lingual and buccal surfaces, and to extend the cervical margins of the 
cavities down to or beneath the free margin of the gum. 

Next, the fillings must be carefully inserted, built out to fully 
restore the original contour, and most perfectly finished. When this 
has been done and the teeth have returned to their former positions 
the approximal surfaces will be in a better condition to resist the influ- 
ences of decay than they originally were, for any changes in the char- 
acter of the saliva cannot affect the gold, and while the cervical border 
of the filling is protected by being constantly covered by saliva the 
lateral borders are so far out upon their respective surfaces as to be sub- 
ject to the cleansing influences of the lips and tongue. 

In addition to this, and scarcely less important, the restoration of 
contour on the approximal surfaces affords normal protection to the 
tender gingivae by preventing the lodgment and pressure of food upon 
them. 

The contour method of filling, based as it is upon physiological, 
anatomical, and mechanical principles, has become the accepted method 
of operating. Experience has proved it to be the only rational method 
of treatment of approximal surfaces, for by it we secure all the desir- 
able conditions of preservation of the natural outline of the teeth, 
necessary contact, immunity from future decay, and protection of the 
gum margins. Its practice involves some sacrifice of healthy tooth 
structure along the buccal and lingual aspects, as well as greater ex- 
penditure of time in filling and finishing, but the results compensate 
for both of these. 

To properly perform the operation of filling and restoration of 
approximal contour requires not only manipulative skill of a high 
order, but also an artistically trained eye in order that the restoration 
may in all respects correspond both in extent and form to the original 
outline of the tooth ; both of these requisites will be acquired through 
frequent repetition. In certain cases, as where the teeth originally were 
not quite in contact, the contour may be advantageously exaggerated in 
order to close the space, but it should never be less than normal or the 
result will not be satisfactory. 

In the filling of an approximal surface next to a space, as where a 
tooth has been lost, the necessity for full restoration of contour does 
not exist and is not absolutely demanded, although a more artistic result 
is secured by its performance in all cases. 



CHAPTER XII. 

THE OPERATION OF FILLING CAVITIES WITH METALLIC 
FOILS AND THEIR SEVERAL MODIFICATIONS. 

By Edwin T. Darby, D. D. S., M. D. 



In the selection of a filling material the operator should consider the 
character of the secretions of the oral cavity, the position of the tooth 
to be filled, the extent of the diseased area, the physical structure of the 
tooth, and the strength of the cavity walls. A filling material must 
possess certain inherent qualifications, the most important of which are 
adaptability, indestructibility, non-conductivity, hardness, absence of 
shrinkage, harmony of color, and ease of manipulation. All of these 
are not to be realized in any one material, and yet some of the more 
important are to be found in a single metal or in a combination of 
metals. 

Lead possesses the quality of softness and is easy of adaptation but 
is readily oxidized when exposed to the air or the secretions of the 
mouth. Likewise tin possesses characteristics, such for instance as duc- 
tility and softness, low conducting power, and the ease with which it 
may be manipulated, which place it in the front rank as a preservative 
of carious teeth, but it is inharmonious in color, and its very softness, 
which is so desirable in manipulation, is an obstacle to its use upon 
surfaces where there is much attrition. The zinc phosphates, which are 
composed of zinc oxid and phosphoric acid in solution, form a com- 
bination which at first attracted the favorable attention of the dental 
surgeon as possible substitutes for metallic foil fillings. They possess, 
owing to their plasticity, ease of manipulation, harmony of color, com- 
parative non-conductivity, and absence of shrinkage, many desirable 
qualities, but are lacking in one essential qualification, namely, inde- 
structibility. 

Gold. 

Gold, which has been used for about a century, has fulfilled in a 
more marked degree than any other material or combination of materials 
the requirements sought for in a filling for carious teeth. It has one or 
two objectionable features, such as high conductivity of heat and inhar- 
monious color. 

267 



268 THE OPERATION OF FILLING CAVITIES. 

Too much stress cannot be laid upon the question of its purity if the 
best results are to be obtained from its use. While it is claimed by 
manufacturers of dental gold foil that their products are absolutely free 
from alloy, it is nevertheless true that but few specimens of dental foil 
show a fineness above 999. If this standard were always attained the 
operator would have little cause for complaint. So small a percentage 
of alloy as 1 in 1000 would not materially affect the working qualities 
of the product, but when this is increased to 4 or 6 parts per 1000 it 
manifests itself by harshness and intractability under the instrument. 

Great care should be exercised in the preparation of the foil, since 
so much depends upon its purity and cleanliness. For a detailed 
description of the process of manufacture, from the ingot to the beaten 
and annealed foil, the reader is referred to an article by a practical foil- 
maker. 1 

In former times the dental surgeon was restricted to one form 
of gold for filling. This was foil ranging in thickness from 4 to 10 
grains to the leaf, but as the requirements of the operator broadened 
the art of manufacture increased, and new preparations were offered, 
until to-day the most fastidious can find such as will please his fancy : 
foils ranging in weight from 4 to 120 grains to the leaf; cylinders of 
various sizes and composed of non-cohesive and semi-cohesive foil ; cohe- 
sive blocks prepared for use ; rolled gold, varying in thickness from No. 
30 to 120, and crystal gold possessing great cohesive properties. These 
are the more important forms in which gold is offered the operator at 
the present time. 

Before entering upon a description of the classes of cases where each 
of these seems best adapted, it may be well to describe somewhat in 
detail the peculiar qualities which each form of gold presents when 
subjected to clinical use. 

Soft or Non-cohesive Foil. — Prior to 1854, when Dr. Robert 
Arthur discovered and promulgated the desirability of cohesive foil in 
certain cases, the operator used gold which possessed very low cohesive 
properties. Used as it then was, in the form of large rope, tape, or as 
cylinders, the property of cohesion would have been a serious objection, 
since there would be constant danger of the mass clogging and bridging 
in the cavity, and the cause of many unfilled places along the cavity 
walls. 

The terms soft and hard, when used to designate the kind of gold, are 
misleading, since all gold foil prepared from pure gold or gold that is 
nearly pure possesses great softness under the instrument. The distin- 
guishing characteristics between the two kinds of gold are the inability 
to make a certain kind of foil cohesive when exposed to a reasonable 
1 American System of Dentistry, vol. iii. p. 839. 



GOLD. 269 

degree of heat, and the ability to render another make of equal purity 
cohesive by the application of a similar degree of heat. It has been 
claimed by some manufacturers of dental gold foils that they are able 
to procure from the same ingot samples of non-cohesive, semi-cohesive, 
and extra-cohesive gold, attaining these physical properties of the mate- 
rial without alloying with other metals. This has led to the belief 
that, since absolutely pure gold possesses inherent cohesive properties, 
some metallic salt or other foreign substance has been deposited upon 
the surface of the leaf of non-cohesive foil which has the power of pre- 
venting the union of the surfaces of the foil when contact is sought. 
It has been surmised that a thin film of iron has been deposited upon 
the surfaces of the leaf of non-cohesive foil, for the reason that if a 
leaf of such foil be melted into a globule, it presents a reddish brown 
appearance, which is not true of the leaf of cohesive foil when melted 
as above. 

Much of the so-called non-cohesive foil offered for sale is not, 
strictly speaking, of this variety, as the application of moderate heat 
will render it quite cohesive. It possesses the softness peculiar to pure 
gold foil, but it should not be classed with the variety which does not 
weld with other particles of the same metal except when subjected to 
great heat. 

It has been claimed by some that non-cohesive foil has no place in 
dental practice — that any tooth which can be filled with gold may be 
filled with cohesive foil. This statement may be true in the main, but 
it is also true that many teeth having strong cavity walls can be just as 
well filled where a large portion of the filling is made with non-cohe- 
sive foil, and with a great saving of time. Adaptation, not hardness, 
constitutes the saving quality in cavity filling. 

As most non-cohesive foil is prepared in the form of sheets and 
is placed in books containing one-eighth of an ounce, the operator is 
compelled to prepare it in some form suitable for introduction to the 
cavity. The size and shape of the cavity will be some guide as to the 
best method of preparing the gold. The narrow tape, the mat, the 
tightly rolled cylinder, and the roll or rope are the forms best adapted 
for the use of non-cohesive gold foil. 

The tape is best made by taking one-half or one-third of a leaf of 
No. 4 or No. 5 foil, laying it upon a table napkin of medium size folded 
square as it comes from the laundry ; the napkin is then taken in the 
palm of the left hand, and the foil spatula is placed in the middle of 
the piece of foil ; the hand is then closed tightly, thus folding the nap- 
kin, likewise the foil, upon the sides of the spatula. This process is 
repeated until the tape is one-eighth or one-sixteenth inch in width 
(Fig. 222). 



270 



THE OPERATION OF FILLING CAVITIES. 



If mats are required, the foil may be folded twice or three times and 
then folded lengthwise upon itself until mats of any thickness are pro- 
duced, as shown in Fig. 223. 

When non-cohesive cylinders are desired, it is better for the operator 
to make them rather than depend upon the ready-made ones as prepared 
by the manufacturer, since these are usually loosely rolled and more or 
less cohesive. The tape is quickly made into the cylinder by rolling it 



Fig. 222. 



Fig. 223. 



Tapes of gold foil. 



Mats of gold foil. 



upon a five-sided broach to the desired size. The depth of the cavity 
is a guide to the width of the tape, and the width of the tape determines 
the length of the cylinder. These should be somewhat longer than the 
depth of the cavity. The manner of introducing and condensing will 
be described later when special cases are under consideration. 

The roll, or " rope " as it was formerly called, is made in the following 
way : A leaf or half leaf or a third of a leaf of foil is rolled between the 

Fig. 224. 




Device for rolling gold foil. 

thumb and finger until a roll of moderate density is obtained. As foil 
is contaminated by contact with the moisture and surface impurities of 
the hands, it is better to avoid such contact as much as possible. This 
can be completely attained by rolling it upon the little device shown in 
Fig. 224. Any operator can make one of these by taking two pieces of 
thin board, such for instance as the lid of a cigar box, and fastening 
to the two pieces with glue a piece of white kid about eight inches in 



GOLD. 271 

length, and in width equal to the sheet of foil. . Two little drawer- 
knobs of ebony should be inserted into the centre of each of the pieces 
of board. These act the part of handles for holding the appliance. 
The gold is then placed upon the kid strip between the two pieces of 
board, and by bringing the two surfaces of the kid in contact the foil is 
rolled between them. The undressed surface of the kid should be the 
one upon which the gold is rolled. Ropes thus made may be cut in 
lengths to suit the size of the cavity to be filled, and, as gold thus pre- 
pared has great softness and ease of adaptation, it may be inserted in 
quite large pieces if plenty of condensing force be applied to it. 

Cohesive Gold Foil. — All gold which has been refined by any of 
the ordinary methods and is in a pure state may be said to be cohesive. 
Nor is absolute freedom from alloy an absolute necessity. It has been 
shown that softness is dependent upon purity, but a foil may contain 
quite a percentage of silver, copper, palladium, or zinc, and yet its 
cohesion may not be impaired. It may also be alloyed or combined 
with platinum and not lose its cohesive properties. It is, however, 
desirable that cohesive gold be pure, since the smallest percentage of 
alloy destroys its softness. 

When two sheets or lamina? of freshly annealed foil are brought into 
contact and slight pressure is applied, they form a permanent union and 
are practically inseparable. It is this property in gold to which the 
term cohesive has been applied. But this property is soon lost by the 
occlusion of gases or impurities of any kind which may be deposited 
upon the surface of the gold. 1 

Experiments have demonstrated the fact that if the gold be sub- 
jected to the fumes of ammonia, hydrogen, hydrogen carbid, hydrogen 
phosphid, or sulfurous acid gas its cohesive property is quickly de- 
stroyed, but this property may be restored by heat except in the case 
of sulfur or phosphorus fumes. Hence the importance of excluding 
the gold as much as possible from the atmosphere, especially during the 
winter months when gases arising from the combustion of coal are most 
liable to be present in the operating room. 

Dr. Black has shown that ammoniacal gas has the power to prevent 
the deleterious influence of other gases, and recommends that the foil 
be subjected to the influence of carbonate of ammonia by keeping it in 
a drawer with a bottle of that salt. 

The advantages of cohesive foil cannot be overestimated. With its 
introduction in 1855 began a new era in the possibilities of saving cari- 
ous teeth. Operations which were deemed impossible by the use of 
non-cohesive foil were made comparatively easy by the intelligent use 
of cohesive foil. The restoration of broken-down or badly decayed 

1 G. V. Black, Dental Cosmos, vol. xvii. p. 138. 



272 



THE OPERATION OF FILLING CAVITIES. 



teeth became the common practice in the hands of the skillful, and mod- 
ern methods of practice coupled with intelligent use of this form of 
gold have made it possible for the operator of modern times to do that 
which the earlier practitioner deemed impossible. 

The beginner, however, must not lose sight of the fact that cohesive 
foil cannot be worked after the same methods as non-cohesive foil. To 
use cohesive foil in the form of mats or cylinders or in tightly rolled 
ropes would mean inevitable failure in adaptation. The very property 
which renders it valuable in the restoration of broken-down teeth and in 
surfacing is the one which would condemn it if used carelessly in the 
interior of inaccessible cavities. Non-cohesive gold may be introduced 
into a well-shaped cavity in large masses, and because of its softness 
and ease of adaptation may be made to touch all points of the cavity 
walls if persistent pressure be applied. On the contrary, cohesive foil 
should be introduced in small pieces, the first of which should be well 
anchored in a retaining pit or groove and each subsequent piece welded 
thereto. 

There are several modes of preparing the beaten cohesive gold foil 
for the cavity, and good results are obtained by either of the following 
methods. 

A loosely rolled rope made of a quarter sheet of No. 4 or 5 foil 
may be cut into lengths varying from one-eighth to one-quarter of 

Fig. 225. 




Ribbons and strips. 



an inch, and after annealing carried to the cavity upon the point of 
the plugging instrument. Or a leaf may be folded with a spatula four 



GOLD. 273 

times, making a broad ribbon, which may be cut either lengthwise or 
crosswise of the ribbon in pieces one-sixteenth or one-eighth of an inch 
in width (see Fig. 225). This is a very convenient manner of working 
cohesive gold. Or the heavier foil up to No. 20 or No. 30 in thickness 
may be cut in strips of a single thickness and of the widths above indi- 
cated, and after annealing may be packed into the cavity — the essential 
idea being ever in mind, that but a small quantity of the gold shall be 
under the instrument at a given time. Cohesive gold which has been 
rolled instead of beaten to the desired thickness is much prized by some. 
It has been asserted that greater softness is obtained when gold has been 
thus prepared. Such gold should not be more than No. 20 or No. 30 
in thickness to insure the best results. It should be cut in narrow 
strips and after annealing be folded back and forth as rapidly only as 
each previous fold has been well condensed. Good results are only 
attainable if each lamina be thoroughly welded. 

The loosely rolled cylinders and blocks which are prepared by some 
dealers and offered as cohesive gold are usually but slightly cohesive, 
and if used in this form, without re-annealing, may be packed in the 
interior of cavities without danger of clogging, but if freshly annealed 
they are contraindicated, since there is more or less danger of imper- 
fect union of all particles of the gold. It is questionable whether the 
larger sizes are admissible when the filling extends beyond the cavity 
walls and great solidity is an essential factor. 

Crystal Gold. — This form of gold was introduced by Mr. A. J. 
Watts in 1853, and as prepared at the present time is one of the best 
preparations of cohesive gold. When first brought out the method of 
manufacture was faulty, since it was difficult or impossible to rid the 
spongy mass of nitric acid which was used in its preparation, but since 
Mr. Watts adopted electrolysis instead of chemical precipitation the 
objectionable features no longer exist. Gold thus prepared manifests 
great cohesive properties, and when used with care as beautiful opera- 
tions can be made with this gold as with any form of cohesive foil. The 
operator should not lose sight of the fact that the gold is to be intro- 
duced into the cavity in small quantities. Should failure attend its 
use, it would doubtless be from the attempt to introduce it too rapidly. 
Gold of this variety comes in bricks containing one-eighth of an ounce 
each, and is either torn apart in irregular-shaped pieces or cut by means 
of a razor into small cubes. This gold should be excluded as much as 
possible from the atmosphere and when used should be well annealed, 
although when recently made it is quite cohesive. There is no prepara- 
tion of gold better adapted for starting fillings in shallow or irregular 
cavities, or for surfacing fillings. Many operators make use of it 

always for starting and for finishing fillings, 
is 



274 THE OPERATION OF FILLING CAVITIES. 

Crystal Mat Gold. — This is another form of crystal gold, and 
differs from that previously described in that it presents a more compact 
form, the crystals appearing smaller and matted together. It breaks 
and crumbles under the instrument to a greater degree than the other, 
and possesses no desirable qualities which the other has not. If it has 
any merit it is for finishing the fillings upon occlusal surfaces, or such 
surfaces as are easy of access, or it may be used in conjunction with 
amalgam. 

Gold and Platinum. — This form of gold has found much favor 
with many practitioners for the restoration of incisal edges, or where 
for any reason great hardness of surface is desired. 

An ingot or bar of pure gold and one of platinum are " sweated " 
together and then rolled to the desired thinness, usually about that of 
No. 20 or No. 30 foil. It is then cut into narrow strips, freshly an- 
nealed and used after the same manner as heavy foil. The commingling 
of the platinum with the gold gives the filling a tint more nearly the 
shade of the tooth, and for this reason it is much used upon labial sur- 
faces and in mouths where the teeth are much exposed. 

Gold thus combined with platinum is much more rigid than gold 
alone, and is contraindicated for making the bulk of most fillings. The 
best results are obtained from it when the mallet is used for its con- 
densation throughout. 



Annealing Gold. 

After the manufacturer has reduced the gold to the desired thinness 
by beating, his last act before booking it is to heat it ; this is termed 
annealing. The object of this is to remove any harshness which has 
been given to it by the process of beating. All metals become more or 
less stiff or rigid by hammering, but become soft again by the applica- 
tion of considerable heat. Gold foil which has been recently made and 
excluded from the atmosphere or certain gases, as previously men- 
tioned, may present sufficient cohesive properties to weld satisfactorily, 
but this property is soon lost, and reheating becomes necessary if it is 
desirable to get union of the various layers. 

Most operators make use of an alcohol flame for annealing gold ; 
others a small Bunsen gas burner. Some hold the piece of gold to be 
annealed in the direct flame or a little above it ; others place the gold 
upon a tray of Russia iron, mica, or platinum and hold this in the flame 
of the lamp or gas jet. This latter method is safest, since there are apt 
to be impurities in the flame dependent upon a charred wick, a particle 
of phosphorus dropping into the wick from the burning match, or, in 
the case of the gas jet, imperfect combustion which might give either 



INTRODUCTION OF THE GOLD. 275 

carbon or sulfur deposits upon the surface of the gold. All or any 
of these accidents would impair the working qualities of the gold. 

The most satisfactory method of annealing gold is by the use of the 
Electric Annealing Tray. Such a device has been invented by Dr. L. 
E. Custer, and is shown in Fig. 226. By this method the gold can be 

Fig. 226. 




Custer's electric annealing tray. 

heated to any desired degree and with a uniformity not easily attained 
by the methods generally used. The working qualities of foil whether 
non-cohesive or cohesive are greatly enhanced by the application of 
heat at the time of using. Gold that is absolutely non-cohesive is made 
tougher by annealing and yet its softness is not impaired, while cohesive 
gold may be made either slightly or decidedly cohesive according as 
much or little heat may be applied to it. It is the practice of many 
operators to use the gold but slightly cohesive when filling cavities sur- 
rounded by strong walls, and the gold known as semi-cohesive, in the 
form of loosely rolled cylinders, is much used. As the filling approaches 
completion the cylinders are heated and additional cohesive property 
imparted to them. But when the object is the restoration of contour or 
building up of teeth which have been broken, the gold should be heated 
but little short of redness in order that the greatest cohesive property 
may be realized. 

Introduction of the Gold, and Manner of Adapting It to 
the Walls of the Cavity. 

It has been shown in Chapter VIII. that few cavities are of proper 
shape for retaining the filling when the decay alone has been removed. 
Most cavities require to be given a retentive shape so that the filling 
shall not be dislodged during its introduction or by mastication or 
otherwise after its completion. In former times, when the operator was 
restricted to one form of gold and that the non-cohesive variety, he was 
compelled to prepare his cavities accordingly ; but at the present time, 
when the variety is almost endless, he can shape his cavity with a view 



276 THE OPERATION OF FILLING CAVITIES. 

to conserving tooth structure, and when he has given it a shape to please 
him he can select, from the many, a special form of gold that will meet 
his requirements. 

There are certain principles involved in the packing of gold which 
must be borne in mind, and the operator should study these before 
introducing his filling. The first of these is force, and the direction and 
relation of that force to the object to be attained. If a given cavity is 
to be filled with non-cohesive gold the operator must take into consid- 
eration the strength of the cavity walls, and must determine whether by 
the wedging process which he will exercise in the effort to adapt the 
gold to the walls of the cavity he will run the risk of breaking them. 

Non-cohesive gold is usually introduced by what is known as hand 
pressure. Each layer of gold is carried to the floor and the walls of 
the cavity by a process of wedging, and the mechanical arrangement of 
each piece of gold should be such that no portion of the gold can es- 
cape when the filling is completed. It will be shown later on, when 
considering the various types of cavities to be filled, that in small cav- 
ities of simple shape the gold prepared in the form of tape is best 
suited, whereas in compound cavities or those of greater size the gold 
may be introduced in the form of compact cylinders or blocks. 

When it is desirable to use a combination of non-cohesive and cohe- 
sive gold, the former is generally introduced first and the cohesive is in- 
corporated with it by driving or forcing layers of cohesive into the non- 
cohesive. This is best effected by using single layers of heavy foil or 
rolled gold of a thickness equal to 20, 30, or 40 grains to the leaf. If 
the filling is to be made of but one kind of gold and that the cohesive 
variety, both hand pressure and percussion by means of the mallet 
may advantageously be employed. The operator who has learned .to 
combine the two forms of gold and is not restricted to either method 
of packing is best qualified for the requirements which are presented in 
general practice. Perfect adaptation to the walls may be effected by 
either method, but greater celerity and the attainment of equal excel- 
lence may be reached by combining the two. 

Plugging- Instruments. — In the selection of instruments for pack- 
ing gold the operator should have a sufficient number to meet his every 
need. They should be of such a variety of patterns that every part of 
every cavity, however remote, can be reached with ease. It is a mis- 
taken notion that a large number of instruments (if well selected) is 
confusing. The operator should study his instruments and know their 
uses as thoroughly as he knows the letters of the alphabet, and if this 
be done and they be arranged in an orderly manner in his case, the 
confusion will be manifest in their absence, not in the possession of 
them. 



INTRODUCTION OF THE GOLD. 



277 



For packing non-cohesive foil none are better adapted than the set 
shown in Fig. 227, made from patterns furnished by Dr. B. J. Bing. 

Fig. 227. 




14 15 16 17 

Dr. Bing's set of pluggers. 

This set should be supplemented by a small and a medium 
sized foot-shaped condenser (Fig. 228), for packing FlG 2 28. 
cylinders, mats, or blocks against the cervical wall. 
The handles of instruments used for packing 
non-cohesive foil should be of such size that they 
can be grasped firmly in the hand. When made 
of wood they are light in weight and agreeable to 
touch. Plugging instruments should have as few 
curves and angles as is consistent with the ability 
to reach all points in the cavity. As these are 
multiplied, direct force is sacrificed. The point of 
the instrument should be as nearly as possible in a 
line with the shaft. Deviations from this rule are sometimes necessary 
in order to reach all points in the cavity. Most plugging instruments 
have serrated points and are used for all forms of gold. As a rule these 
serrations should be shallow, and when cohesive gold is to be employed 
they should be only sufficient to prevent slipping, as gold that is quite 
cohesive packs as readily with smooth points as with rough ones. 




278 



THE OPERATION OF FILLING CAVITIES. 
Fig. 230. 

Fig. 231. 



Fig. 229. 



il 



Snow and Lewis auto- The Abbott mallet 

matic mallet. 




S. S. White electric mallet " No. 2. 
Founded on the "Bonwill." 



INTRODUCTION OF THE GOLD. 279 

It is not definitely known when packing gold by percussion was first 
suggested, but the idea is quite generally accorded to Dr. E. Merrit of 
Pittsburg, who as early as 1838 used the hand mallet for condensing 
the surface of fillings which had been introduced by hand pressure. 
The first mallets used were of light weight and were made of wood or 
ivory. As the method became more general, heavier mallets were em- 
ployed, and those made of lead, tin, various alloys, and steel found much 
favor. Before the introduction of rubber dam for excluding moisture 
one hand of the operator was employed in holding the napkin, and it 
became necessary to have an assistant at hand to do the malleting. 
This led ingenious minds to discover some means of percussion besides 
the hand mallet, and several spring instruments known as automatic 
pluggers were introduced. The Snow and Lewis, the Foote, and the 
Salmon found greatest favor, and all of them were good of their kind. 
The accompanying cut (Fig. 229) shows the Snow and Lewis Automatic 
Mallet as made at the present time. When pressure is applied to the 
point of the instrument a spring is liberated which throws a plunger 
forward with great force, which is expended upon the gold beneath the 
point. The impacting quality of this blow is not excelled by any of 
the mechanical devices in use. It is so constructed that a light or a 
heavy blow can be given at will. The operator will do well to adjust 
the instrument for light blows when using it in close proximity to frail 
or delicate walls, as there is more or less danger of fracturing them. 

Instruments of this class are not well adapted to packing gold in 
the posterior teeth of the lower jaw, as the blow is delivered at a more 
or less acute angle, and unless care be exercised when the operation is 
nearing completion the plugger point will slip from the surface of the 
filling and wound the soft tissues. 

Another instrument of this type devised by Dr. Frank Abbott (see 
Fig. 230) has a socket at either end of the hand-piece, the one giving a 
pushing and the other a pulling blow. The latter is serviceable for 
condensing gold upon distal surfaces. 

The electric mallet is one of the most ingenious devices em- 
ployed in dentistry. The first practical application of electro-magnetic 
force for dental malleting was made by the late Dr. W. G. A. Bon will. 
Its latest development is shown in Fig. 231. This instrument has 
found great favor among dentists for packing cohesive gold. Its blows 
are delivered with great rapidity and with such force that great solidity 
is attainable. A pair of electro-magnets transforms the electric current 
into electro-magnetic force, which is transmitted to the hammer. The 
electric current is furnished by a Bunsen or Partz battery, or the con- 
trolled current from a dynamo or storage battery can be used as the 
motive power. In the hands of a skilful operator there could be nothing 



280 



THE OPERATION OF FILLING CAVITIES. 



better for packing cohesive 
gold. The best results are 
obtained by its use when the 
gold is prepared in thin lam- 
inae or where a single thick- 
ness of heavy foil or rolled 
gold is employed. 

Considerable experience is necessary to 
enable the operator to use this instrument 
with satisfaction to himself and his patient. 
If the plugger point be pressed hard against 
the filling, the blows, which are delivered with 
great rapidity and force, become painful and dis- 
tressing and there is also danger of chipping the 
cavity walls. The better plan is to hold the point 
slightly away from the surface of the filling and 
allow the momentum which is given the instru- 
ment by the falling armature to complete the 
union of the various pieces of gold. 

The engine mallet (see Fig. 232) is intended 
for use upon the dental engine. It is made with 
a slip joint and can be applied in place of the 
hand-piece to nearly all of the dental engines in 
use, although it is best adapted to one of the 
" cord " engines because of the greater freedom 
of action. The instrument shown in the illus- 
tration embodies many improvements in con- 
struction which have been suggested by various 
operators since the " Bonwill mechanical mallet 
on which it is based, was introduced, and a point 
of relative perfection has been reached where are 
combined great efficiency with compactness and 
lightness in handling. It will be seen by the 
illustration that the essential feature of this in- 
strument is a revolving wheel having inserted in 
its periphery a hollow cylindrical steel roller. 
This constitutes the hammer. It gives a " spring," 
not a " dead " blow, as it is held to its position by 
a stiff steel spring. The roller revolves slightly 
in its socket at each contact Avith the plunger. 
When the engine is run at ordinary speed the 
small wheel revolves with great velocity, deliver- 
ing upon the head of the plunger as many as fif- 



Fig. 232. 

Engine Mallet. 





INTRODUCTION OF THE GOLD. 



281 



teen blows per second. The force of the blow can be modified at will 
by an extremely simple contrivance, as follows : The interdigitations 
seen around the upper end of the sleeve are held together by means of 
a spring attached to the sleeve. Pulling the sleeve away from the head 
against the spring, and revolving it to the right or left, raises or lowers 
the head of the plunger. Upon releasing the sleeve the spring at once 
throws it back to engage with the head, and the blow is heavier or 
lighter, according to the direction in which the sleeve has been revolved. 
The impacting power of the blow from this is great, and in the 
hands of an experienced operator a large quantity of gold can be con- 




^\ 



Fig. 233. 



1 \ \\ 



^ 



^ 




Varney's set. 



\ 




; iff /'if 1 1 



Chappell's set. 

densed in a short space of time. When cohesive gold foil is employed 
smooth oval points may be used with most satisfactory results. The 
point should not be pressed hard against the filling, but a skimming or 
smoothing motion given to the instrument. The surface of the filling 
when thus packed has a polished or planished appearance as if done 
with a hand burnisher. Such fillings are usually of great density. 

There are other mechanical mallets intended for use on the engine 
which have what is known as a " cam " movement. They are not, 



282 THE OPERATION OF FILLING CAVITIES. 

strictly speaking, mallets, for the instrument is pushed rather than 
driven forward by an eccentric. The Buckingham and the Holmes 
mallets belong to this class. They have not the same steadiness of 
motion as the ones previously described, and for this reason, among 
others, have not been in general use. 

In the selection of plugger points for power mallets the operator will 
do well to confine himself to those having more than one row of serra- 
tions and those which are smooth-faced. The serrations, if any, should 
be extremely shallow, and the corners of the instrument slightly 
rounded. Those of the foot-shaped variety are admirably adapted to 
power mallets, and as there is a great variety of patterns and sizes he 
will have little difficulty in meeting his every wish in this particular. 
A few points selected from the Webb, the Varney, and the Chappell 
sets will fill all requirements. The accompanying cut (Fig. 233) shows 
a good working set which has been selected from the three mentioned. 

Filling — by Classes. 

(As arranged in Chapter VIII.) 

I. Simple Cavities on Exposed Surfaces. 
Bicuspids and Molars. 
Class A. — The small cavities upon the occlusal surfaces of the 
bicuspids and molars are among the simplest in form. They are shown 
in Chapter VIII., Fig. 173. Cavities of this kind are quickly filled 
by means of non-cohesive foil in the form of tape as shown in Fig. 
222. Such cavities are usually of regular shape and of a form re- 
quiring little if any additional shaping to make them retentive. A 
length of tape varying from an inch to two inches should be taken 
upon a wedge-shaped plugger point and carried to the bottom of 
the cavity, where it may be held for an instant with a point in the 
left hand ; the instrument in the right hand makes a fold of the gold 
and carries it into and against the walls of the cavity by a lateral mo- 
tion ; fold after fold is then carried into the cavity and pressed firmly 

in every direction. As it is always best to finish such fill- 
Fig 234. 

ings with cohesive gold, a strip of No. 20 cohesive foil 

should be wedged into the mass already in the cavity, and 
then all subsequent pieces malleted, to give the occlusal 
surface as great hardness as possible. A completed filling 
of this class is shown in Fig. 234. Perfect adaptation to 
the walls of the cavity is obtained by the use of the non- 
cohesive foil, and great solidity is only essential upon the surface. 
Cavities of this character, though of greater size, are found in the 
molars, as shown in Figs. 235-237, and may be filled in the same gen- 




SIMPLE CAVITIES ON EXPOSED SURFACES. 



283 



eral way. Mats of foil may be substituted for tape, and where the decay 
has progressed to such an extent as to involve a large portion of the 
occlusal surface, making, as is frequently found, large round and quite 
deep cavities, the gold may be introduced in the form of cylinders. 
In former times, when the dentist's only means of excluding moisture 



Fig. 235. 



Fig. 236. 



Fig. 237. 






Fig. 238. 




Fillings in molar fissure cavities. 

was the napkin, and when his ability to keep cavities free from saliva 
was for a limited time only, the use of cylinders was much more com- 
mon than at the present time when the rubber dam is generally em- 
ployed. 

Cylinders for such cavities should be hand-made and of No. 4 non- 
cohesive foil (Fig. 238). They should be long enough to extend above 
the margins of the cavity as shown in Fig. 238 and arranged 
around its walls. The first one is usually carried to that 
point in the cavity farthest away, and should be pressed with 
a foot-shaped instrument against the wall. Others are then 
put in place and wedged laterally until room is made in the 
centre of the mass for another cylinder, this in turn being 
wedged toward the outer walls, and the operation continued 
until no more cylinders can be introduced. The cylinders 
should then be condensed with great force upon their pro- 
truding ends, and finished with cohesive foil in the same 
manner as previously described. This mode of filling is best suited to 
deep cavities in which the walls are nearly parallel and yet sufficiently 
strong to endure great lateral pressure. 

In a cavity of unequal depth, where the central portion is quite deep 
and the sulci radiating from it quite shallow (see Fig. 239), it is well to 
use semi-cohesive foil in the central portion and cohesive 
foil in the radiating sulci. Such fillings require to be well 
anchored at the extremities of the fissures lest they be dis- 
lodged by sticky candy, which often adheres with great 
tenacity to the surface of the gold. The operator will do 
well in filling such cavities to confine himself to gold that 
is quite cohesive, except in the central portion as above 
indicated. 
Class B. — Cavities situated upon the buccal surfaces of the bicus- 
pids and molars are rather more difficult to fill because of the difficulty 
in getting the rubber dam beyond the cervical border of the cavity. 



Fig. 239. 




Filled stellate 
cavity in 
lower first 
molar. 



284 



THE OPERATION OF FILLING CAVITIES. 



Fig. 240. 




Buccal cavity 
in lower sec- 
ond molar. 



When this has been done and perfect dryness effected these cavities may 
be classed as simple ones. 

In small or non-elastic months it is often difficult to reach the second 
or third molars, hence the view of the cavity is somewhat impaired. 
In selecting the gold for such cavities the operator must 
take into consideration the depth of the cavity. If it be 
shallow he will do better to start his filling in a retaining 
pit and fill throughout with cohesive foil. If, on the con- 
trary, the cavity be of considerable depth, he may fill the 
bulk of the cavity with mats or tape made of non -cohesive 
foil, and, as he approaches the surface of the filling, incor- 
porate with it cohesive gold and finish his operation with 
the last-named variety. Such cavities are often advantageously filled 
throughout with Watts' crystal gold. This form of gold is easily seated 
and it has no tendency to rock or move in the cavity. A slight under- 
cut along the upper and lower border of the cavity is sufficient to hold 
the filling in place (Fig. 240). 

When these cavities assume larger proportions, as they frequently do 
in the lower molars, and become confluent with cavities on the occlusal 
surface, they should be filled after the following method : A mat or 
block of non-cohesive foil should be placed at the border nearest the 
gum ; this may be held for a moment with an instrument in the left 
hand. One or two other blocks may be laid against this, and, when 
they have been well fixed in the undercut, should be malleted thoroughly 
against the cervical border ; the remainder of the cavity may then be 
filled with semi-cohesive or cohesive gold. The surfacing of all fillings 
should be done with gold which has been made cohesive by recent 
annealing. 

Class C. — Cavities do not often occur on the lingual surfaces of the 
bicuspids or molars except in teeth of very poor structure and in teeth 
from which the gum has receded to a point below the enamel border. 
Such cavities because of their inaccessible position are difficult to fill 
with gold, and, as a rule, some of the plastics are indicated. When the 
fissures on the upper molars become the seat of caries they may be 
filled with gold in the same manner as those in class B. It is usually 
necessary to pack the gold in these cases almost entirely by hand pres- 
sure because of the inaccessible situation of the cavity. 



Incisors and Canines. 

Class D. — Cavities upon the labial surfaces of the incisors and canines 
situated at or near the gingival border of the gum were formerly the 
source of much annoyance to the dentist when gold was the material 
selected for filling. The principal difficulty was occasioned by mois- 




SIMPLE CAVITIES ON EXPOSED SURFACES. 285 

ture, either in the form of blood or serum from the wounded gum or 
mucus from the follicles situated along the mucous surface. Since the 
introduction of the rubber dam this difficulty has been greatly modified. 
But when the cavity extends somewhat above the nor- 
mal gum line there is more or less difficulty in keeping 
the rubber above the gingival border of the cavity. This 
is best done by taking a straight instrument the point 
of which has been made very sharp by rubbing it upon 
an Arkansas hone. The dam is then raised well above 
the cavity border and the point pressed firmly into the 
dentin and held with the left hand throughout the ope- 

« «-it -, . a Till Woodward clamp. 

ration oi tilling the cavity. A very neat and valuable 
device in the form of a clamp has been introduced by Dr. W. A. Wood- 
ward for this purpose. It is shown in Fig. 241. 

The dam should include not only the tooth to be filled, but several on 
each side of it. With the left hand it is stretched above the margin 
of the cavity, while with the right hand the two little points on the 
bow of the clamp are pressed firmly into the cementum above the cavity. 
The clamp is then made secure by turning the set-screw. This clamp 
when well seated rarely fails, and the operator feels that this difficult 
operation has become a simple one. 

There are cases, however, where the decay has followed the receding 
gum or extended beneath it to such an extent that the clamp cannot be 
used. To overcome this difficulty the gum should be slit and a 
" Mack " screw inserted to the depth of two or three threads into the 
dentin. The rubber dam is then drawn above this and held securely 
above the cavity. When the operation is completed the screw should 
be cut off with the wedge-cutters and nicely smoothed. When the slit 
in the gum has healed, the portion of the screw remaining will be 
concealed. 

Most cavities upon the labial surfaces are shallow and are best filled 

with cohesive foil or Watts' crystal gold. It is well to fix the first piece 

securely in a small retaining pit and build each piece 

Fig. 242. upon a sure foundation, As fillings upon the labial 

surfaces of teeth are usually conspicuous (Fig. 242), 

it is often desirable to fill such cavities with plat- 

inous gold, because the tint of the two metals in 

Labial fillings. combination is more nearly the shade of the tooth. 

Especially is this true in teeth of yellowish hue. 

Class E. — As cavities upon the lingual surface of the incisors are 

usually confined to the laterals and most frequently are the result of 

imperfect development of the enamel in relation to the cingulum (see 

Chapter I., p. 25) ; they are small in size and easily filled. A tape of 





286 THE OPERATION OF FILLING CAVITIES. 

non -cohesive foil, or a small mat of the same material, may be inserted 
into the cavity first, and the filling completed with cohesive gold as in 
other cavities surrounded by strong walls. 

Class F. — As caries rarely attacks the incisal edge of the anterior 
teeth the operation of filling with gold is usually confined to artificially 
made cavities, with the view of arresting waste of tooth substance 
caused by attrition, or where for any reason it is deemed best to " open 
the bite." Great strain is often brought to bear upon fillings in this 
position, and too great care cannot be exercised in the shaping of the 
cavity and the subsequent packing of the gold. 

Cohesive gold is best suited to cavities of this description, and each 
piece should be freshly annealed, that there may be no doubt about the 
perfect union of each piece. It is well to start the first 
piece in a small retaining or starting pit and then fill all 
of the undercut before attempting to build the gold above 
the walls. As fillings in this position are subjected to 
great wear, the greatest hardness of surface attainable 
should be sought for, otherwise there will be battering 
of the edges and possibly flaking of the gold. Platinous 
gold is well adapted for this kind of fillings. Narrow strips of No. 20 
or No. 30, well annealed and condensed with mallet force, will answer 
a better purpose than lighter foil (Fig. 243). 

II. Simple Approximal Cavities. 
Incisors and Canines. 

Class G. — In selecting the kind of gold and the form in which it 
should be prepared for fillings upon the approximal surfaces of the 
incisors and canines, the operator must consider the size of the cavity 
to be filled and the retaining hold which he is able to secure without 
sacrificing too much of the tooth structure. 

If the cavity be a small one, situated midway between the labial and 
palatal walls, and the surrounding borders be strong, a rapid and easy 
way of filling such cavities is to prepare the non-cohesive foil in the 
form of narrow tape. A leaf of foil cut into four pieces and folded 
with a spatula upon a napkin to the width of one-sixteenth of an inch, 
and then cut into lengths of three-quarters or one inch, is a good way 
of preparing it. 

An excavator of an angle of forty-five degrees, with the extreme 
point broken off, makes a very good instrument for packing such 
fillings. Space should previously be obtained, either by the slow pro- 
cess of wedging with rubber or linen tape or by means .of the Perry 
separator. 




COMPOUND CAVITIES. 287 

When the cavity is two-thirds filled it is well to use a few pieces of 
Xo. 20 cohesive foil, so that a dense surface may be given to the filling. 

Such cavities may be classed among the simple ones, and Fig. 244. 
present no difficulties except their inaccessibility (Fig. 244). 

The operator should ever strive to conceal as much as pos- 
sible the gold in the anterior part of the mouth, and when it 
is possible he should preserve the labial wall intact. This Mesio-ap- 
can often be done by cutting away a portion of the palatal P roximal 

J . . incisor 

wall and by packing the filling almost entirely from the under filling. 
side of the tooth. Where a large portion of the approximal surface is 
involved, the retaining hold for the filling must be had at the cervical 
border and at the cutting edge. The first pieces of gold should be an- 
chored in a groove or retaining pit near the cervix and the cervical 
border made secure before any other portion of the cavity is filled. 
The beginner will ordinarily do better to start such fillings Avith cohesive 
foil or Watts' crystal gold. If the latter, he may then complete his 
filling with cohesive foil. Non-cohesive gold is rarely indicated in cav- 
ities of this description. 

The electro-magnetic mallet or the Bonwill mechanical mallet is well 
adapted for packing such fillings. 

Bicuspids and Molars. 

Class H. — Cavities of medium size situated upon the mesial or dis- 
tal surfaces of the bicuspids and molars and not involving the occlusal 
Fig 245 surface may be filled after the same manner as small cav- 
ities in the incisors or canines. Operators who are not in 
the habit of using non-cohesive foil prefer starting such fill- 
ings in a small undercut or retaining pit and filling through- 
out with cohesive gold prepared either in narrow ribbons 

Approximal ° , x * 

bicuspid or loosely rolled cylinders (Fig. 245). 

filling. Such fillings, because of their position, must be packed 

largely by hand pressure, although the mallet may be used as the 
filling approaches completion. 

III. Compound Cavities. 
Incisors and Canines. 

Classes I and J. — Mesio-labial and disto-labial cavities in the incisors 
and canines are usually best filled throughout with cohesive gold. Each 
cavity independent of the others should have retentive shape, so that in 
the event of one filling being displaced the other will remain intact. 

As a rule it is better to fill the cavity on the labial surface first, 
because the first pieces of gold are more easily anchored in an accessible 





288 THE OPERATION OF FILLING CAVITIES. 

cavity, and because also of the danger of displacing the gold in the 
approximal cavity when filling the channel connecting the two fillings. 
Every possible care should be exercised in packing the gold 
Fig. 246. i n cavities of this description. The gold should be made 
thoroughly cohesive by recent annealing, and be used in pieces 
sufficiently small to prevent clogging. Such operations are 
more or less exposed to view, and the greatest degree of 
artistic skill should be bestowed upon them to render them 
as pleasing as possible to the eye. The original outline of 
the tooth should be restored with the gold, because it pre- 
sents a better appearance than a space between it and the adjoining 
tooth (Fig. 246). 

Classes K and L. — Cavities upon the mesio-lingual or disto-lingual 
surfaces of the teeth are filled in precisely the same way as those 
described under classes I and J. If the cavity be of con- 
siderable depth, non-cohesive gold may be used as part of Fig. 247. 
the filling, but in any event the bulk of the filling should 
be made of cohesive foil (Fig. 247). 

Classes M and N. — Mesio-incisal ; Disto-indsal. — Cav- 
ities situated upon the approximal surfaces of the incisors 
and becoming confluent with one on the incisal edge require guai filling. 
great care in the matter of packing gold. It is often an 
advantage to have the cavity on the approximal surface unite with 
a natural or an artificially made one upon the incisal edge, because 
much better anchorage can be obtained in such cavities. Cohesive 
gold prepared in the form of ribbon or in pellets or cohesive cylin- 
ders, if loosely rolled, may be used. The better method is to fill 
the undercut at the cervical border of the cavity first, and then bring 
the gold toward the incisal edge as squarely as possible, keeping the 
mass on a line with the labial and palatal walls. The 
operator feels a sense of security when he is able to an- 
chor such fillings in an undercut or retaining pit on the 
incisal edge. In teeth with broad incisal edges there is 
ample opportunity to make a strong retaining hold, but 
where the edge is narrow a lateral cut into the palatal Mesio-incisai _ 

. . filling. 

wall one-third back from the incisal edge affords a strong 
and secure hold for that portion of the filling. Operations of this class 
require great thoroughness in the packing of the gold. It should be 
very cohesive and when possible condensed with some form of mallet 
(Fig. 248). 

Class 0. — Mesio-disto-incisal — Where both approximal surfaces 
and the incisal edge are united in one cavity, the better plan is to begin 
the filling at the undercut near the cervical border of the distal cavity, 





COMPOVND CAVITIES. 289 

and build the gold squarely down as in classes M and N until the in- 
cisal edge is reached, thence across the incisal edge, then fill the mesial 
cavity after the same manner, uniting the three fillings at the mesio- 
incisal corner. It is better to insert such fillings with an 
electric or a mechanical mallet, as there is always dan- 
ger, when packing across the incisal edge by hand pres- 
sure, of pushing one or the other of the fillings out of 
the approximal surfaces. 

If no accident occurs in the packing of the gold a Mesio-disto-incisai 
filling thus made is very secure, for its form is like a 
staple and each portion helps to bind the others securely in the triple 
cavity. Non-cohesive gold should form no part of such fillings (Fig. 
249).' 

Bicuspids and Molars. 

Class P. — Mesio-occlusal. — The filling of this class of cavities offers 
no serious difficulties provided sufficient space has previously been ob- 
tained. As it is desirable to restore with gold the original outline of 
the tooth, sufficient space to do this in is a necessity, and the operator 
will soon learn that he can only accomplish good results in proportion 
as he recognizes the importance of this preliminary. 

The cervical border is the vulnerable point for recurrence of decay, 
and imperfection here in the matter of packing the gold means speedy 
failure of the filling, hence the importance of a perfect joint between 
gold and tooth. This may be obtained by either non-cohesive or cohe- 
sive gold if due care be exercised in its use. Where the cavity has not 
great depth and the retaining grooves are also shalloAV, no better method 
of laying the cervical foundation can be adopted than by the use of 
Watts' crystal gold or the "Velvet" cylinders, which possess great soft- 
ness and some slight cohesive properties. If the operator has had 
some experience in working non-cohesive foil he will do well to use a 
mat of non-cohesive foil at this point, allowing the mat to extend some- 
what beyond the cervical border of the cavity. This may be followed 
by another mat or two, after which they should be malleted to place, a 
foot-shaped plugger point being used. The upper third or even one- 
half of the cavity may be filled after this method. He should then 
begin the use of cohesive gold. The two kinds can be incorporated as 
previously described and the filling completed with gold which has been 
freshly annealed. 

It is always better to insert too much rather than too little gold, as 
the operator can shape the contour according to his fancy or to the 
necessities of the case. 

The occlusal portion of the filling should be thoroughly condensed, 

19 



290 



THE OPERATION OF FILLING CAVITIES. 



Fig. 250. 




as much depends upon this for holding the filling in place. Great hard- 
ness is also essential to prevent battering in the 
act of mastication (Fig. 250). 

Class Q. — Disbo-occlusal cavities may be filled 
in precisely the same manner as those situated 
upon the mesio-occlusal surface. The difficulties 
are slightly greater because these cavities are not 
so accessible. Cavities of this description can be 
greatly simplified by the use of the matrix. This little device converts 
compound cavities into simple ones, and when used with care and judg- 
ment facilitates the operation of filling to a wonderful degree. It will 
be observed in the Jack matrices (as shown in Fig. 251) that provision 

Fig. 251. 



Approximo-occlusal 
cavities. 



ODDDDD 

The matrices of Dr. Louis Jack. 

has been made for contouring the filling. If this style be employed the 
operator must study the outline which he desires his filling to assume 
and select his matrix accordingly. He must have previously obtained 
ample space between the teeth for the placement of the matrix. 

When put in place the matrix should be thoroughly fixed against the 
tooth to be filled, with wedges of orange wood previously dipped in 

Fig 252. 




Loop matrices. 

moderately thick sandarac varnish. This will keep the wedges from 
slipping. A very good way of fixing the matrix is to pack between it 
and the adjoining tooth some quick-setting oxyphosphate of zinc. If 
the part be thoroughly dry the cement will become adherent to the 
matrix and the adjoining tooth and the matrix will thus be made secure. 



COMPOUND CAVITIES. 



291 



Whenever the matrix is to be employed it must be understood that an 
important feature is absolute fixation of the device, otherwise the ope- 
rator will suffer continual annoyance throughout the operation. 

Where there is sufficient space between the adjoining teeth for a 
band matrix the operator will find great satisfaction in their use (they 

Fig. 253. 




Brophy's band matrices. 



are show^n in Figs. 253, 254), but as most teeth are smaller at the neck 
than at the occlusal surface, there is often difficulty in adjusting the 



Fig. 254. 



■ c • ,o 



f£\ 



pi 



fZ\ 



ra 



f^ 



m 



N^' '^J. ' Vifc" v **o^ 



I 



\kjj v*.^ v__y w* 




Guilford's band matrices and clamps. 

matrix to that portion of the tooth : a wedge used as previously described 
w T ill often overcome this difficulty. 

A modification of the band matrix has been devised by Dr. Guilford, 
and is shown in Figs. 254, 255. It will be seen that space upon both 
sides of the tooth to be filled is unnecessary, as the little clamp binds the 
matrix to the tooth. Another style of matrix, and one admirably 
adapted to many cavities in the bicuspids and molars, has been intro- 
duced by Dr. W. A. Woodward, and is shown in Fig. 256. It will be 
seen that this matrix has two screws which are driven against the 



292 



THE OPERATION OF FILLING CAVITIES. 



adjoining tooth and keep the matrix firmly in place and at the same 
time act as a separator. If the operator feels that he has insufficient 
space, as his filling progresses he can occasionally tighten the screws 
and gradually gain space between the teeth, which is of value when he 
is ready to dress down and polish his filling. Several sizes of these 
should be at hand to meet the exigencies of individual cases. 

It has been said that the matrix converts a compound cavity into a 
simple one. This is accomplished by making of metal a temporary 
fourth wall to the cavity. It must be borne in mind, however, that 

Fig. 255. 





Examples showing uses of matrices. 

the use of the matrix does not lessen the care which should at all times 
be exercised in the packing of the filling. Direct pressure against the 
disto-buccal and disto-lingual borders of the cavity cannot be as well 
obtained when the matrix is used as when it is not, hence the importance 
of having the matrix so adjusted that these walls may be accessible. 

Cavities of this variety seldom require retaining pits. The cavity is 
supposed to be of a retentive form. If the matrix has been made to 
fit the cervical border of the cavity and is thoroughly wedged against 
it, the filling may be started with mats of non-cohesive foil or with loosely 

Fig. 256. 




rolled cylinders. Two, three, or even more may be pressed thoroughly 
against the cervical wall and condensed with a hand mallet or with the 
automatic mallet. Similar pieces are then inserted and malleted to place 
until the upper third of the cavity has been filled. Cohesive gold may 
then be substituted for the non-cohesive and each piece packed with 
hand pressure or mallet force as preferred. The instruments shown in 
Fig. 257 are well adapted to fillings of this description. 

As there is sometimes difficulty in adjusting the matrix to the cer- 
vical bordej^of ? the cavity, it is well at times to insert a cylinder or two 



COMPOUND CAVITIES. 



293 



before putting the matrix in position, letting the ends of the cylinder 
extend beyond the walls and into the space between the teeth. The 
matrix is then put in place and rests upon the protruding ends of the 
cylinders. These are condensed against the cervical border and the 
operation is completed as previously described. The introduction of the 
cylinders as stated, previous to the adjustment of the matrix, contributes 
largely to the successful formation of a tight joint of the gold and the 
cervical border. Or the same object may be accomplished with perhaps 
greater certainty by adjusting a band matrix and screwing it tightly 
into close contact with the tooth surfaces. When this is done there will 
usually be found a slight space between the matrix and the tooth at the 
cervical border, caused by the band standing away from the tooth at 
that margin. In filling this Cavity the first pieces of gold, preferably 
loosely rolled cylinders or mats, are grasped singly by the foil tweezers 
near the end and passed endwise into the space between the matrix and 



nmu urns 




Matrix pluggers. 

the cervical margin of the cavity. The end projecting into the cavity 
is then bent inward and over the cervical margin and pressed firmly 
down upon the cervical wall. Other pieces of gold are then similarly 
introduced and condensed. This forms the foundation of the filling, 
after which the operation is completed with cohesive foil as before de- 
scribed. The advantages of this method are that the first pieces of 
gold by being wedged between the matrix and the neck of the tooth 
are immovably held, thus rendering the usual starting anchorages un- 
necessary. This method also gives positive assurance that the cervical 
border is perfectly filled. The same perfection of joint at the lateral 
margins of the filling may be attained where a band matrix of the Guil- 
ford type is employed by slightly loosening the set-screw of the matrix 
clamp as the operation proceeds, so that the band may be moved from 
contact with the lateral margins of the cavity and the gold carried over 
them as was done at the cervical margin. Moreover, when excessive 
contour is desired it is easily accomplished by a gradual loosening of 



294 THE OPERATION OF FILLING CAVITIES. 

the clamp screw as the operation proceeds and the additional space is 
needed. 

The matrix is best suited to disto-occlusal cavities. It is sometimes 
employed upon mesio-occlusal cavities, but as a rule obstructs the light 
and adds little to the convenience of the operator. 

Experience has demonstrated that the only satisfactory method of 
filling cavities upon the approximal surfaces of the bicuspids and molars 
is to restore , by means of filling material, the original outline of the 
tooth. This is termed " restoration of contour." To do this success- 
fully requires artistic sense and mechanical skill of a high order, and 
an accurate knowledge of the topographical anatomy of the teeth. To 
the man who has these the operation is easy, but otherwise persistent 
effort alone will enable him to acquire the ability. The inexperienced 
operator will often do better if he confine himself in the beginning to 
but one kind of gold, and that of the cohesive variety. If this be done 
he should start the filling in a well-defined groove at the cervical border 
of the cavity, and then add, piece by piece, well-annealed foil until the 
filling is completed. Such a procedure is of necessity slow, but excel- 
lent operations can be made by this method. The beautiful and lasting 
operations of Varney and Webb and others were made in this way. 

Class R. — Occluso-buccal cavities are usually confined to the lower 
molars. If they be shallow it is better to fill throughout with cohe- 
sive gold. If, on the other hand, the cavity upon the occlusal surface 
be deep, non-cohesive gold may be used in part and then cohesive gold 
used to fill the channel connecting the two cavities. Such fillings are 
subjected to great wear and should be solid (Fig. 258). 

Class 8. — Occluso-lingual. — These cavities are nearly always con- 
fined to the first and second upper molars, and as a rule are best filled 

Fig. 258. Fig. 259. Fig. 260. 






Occluso-buccal tilling. Occluso-lingual filling. Mesio-occluso-distal filling. 

with cohesive gold. The channel running into the lingual aspect of 
the tooth is not often deep, and non-cohesive gold is contra-indicated 
(Fig. 259). 

Class T. — Cavities upon the mesial and distal surfaces of the 
bicuspids often become confluent with those upon the occlusal sur- 
face, and it becomes necessary to fill them as one cavity. Such ope- 



FILLING WITH TIN. 295 

rations are simplified by the use of a matrix upon the distal surface. 
A band matrix could be employed, but it obstructs the light somewhat 
and the operator will more frequently confine himself to a matrix upon 
but one side of the tooth. The filling should be commenced at the 
disto-cervical border, and after inserting a few mats or cylinders of 
non-cohesive foil proceed as in cavities described under class Q 
(Fig. 250). 

If these cavities be of considerable size the buccal and lingual walls 
are weakened and there is danger of their being broken away in the act 
of mastication. It is often well to truncate the cusps somewhat and 
build the gold well across the occlusal surface, allowing the strain to 
come directly upon the gold instead of upon the tooth structure. 

Pilling with Tin. 

It is not definitely known when tin was first employed for filling 
carious teeth, but it has been used for at least a century and has found 
great favor with many. Prior to the improvement in the formulas of 
dental amalgams, tin was used more generally than at the present time. 

Tin possesses certain inherent characteristics which make it valuable 
as a filling material. Among these are great malleability, non-conduc- 
tivity, and it is thought by many to possess antiseptic properties. But 
while it has desirable qualities it has also some undesirable ones, such 
as softness, and when exposed to the secretions of the mouth it discolors, 
— which facts render it unfit for surfaces exposed to great wear in the 
act of mastication and upon surfaces exposed to view. The discolora- 
tion, however, is confined to the surface, and teeth filled with tin are not 
discolored in consequence of its presence. 

There are various methods of preparing tin for dental purposes. 
That which has found greatest favor in the past is in the form of foil. 
The tin used should be chemically pure. An ingot of the metal is 
rolled into ribbon and then beaten, after the same manner as gold foil, 
into sheets of the desired thickness. As a rule it is not beaten as thin 
as the former. The foil best suited for most fillings is No. 10. 

Pure tin, like pure gold, is cohesive, and fillings of great solidity 
can be made if the operator will exercise care in packing it. The best 
results are obtained by taking a third of a leaf of No. 10 foil and roll- 
ing it into a loose rope, then cutting it into lengths of half an inch or 
less and packing each piece with a view of making each part of the 
filling solid. Some prefer folding the sheet with a spatula after the 
same manner as gold foil, and then cutting into narrow tape. Equally 
good results are obtainable by either method. 

A more rapid but less satisfactory manner of introducing the fillings 
is to use the tin in the form of cylinders, not relying so much upon the 



296 THE OPERATION OF FILLING CAVITIES. 

cohesive properties of the metal. The directions for using gold in the 
form of cylinders will apply equally well for inserting tin foil. 

Felt Tin. — This form of tin was introduced by Dr. Slayton some 
years ago, and at one time found favor with many operators. Tin thus 
prepared resembles coarse felt, and comes in sheets of various thick- 
nesses, usually about that of billiard cloth. This is cut into squares 
or strips of various widths and packed into the cavity after the same 
manner as tin foil. It appears to possess no advantages over ordinary 
foil prepared as above. 

Shredded Tin. — This form of tin, as its name implies, presents a 
shredded appearance, and it is said to contain a small percentage of 
platinum. It is quite cohesive, and works with a degree of softness 
that is pleasing to the operator. It is claimed for it that cohesive gold 
foil will adhere to it much more readily than to pure tin in the form of 
foil. If this claim be valid the advantages are apparent when the 
operator desires for any reason to use the two metals in combination. 

Shavings of Tin. — The cohesive property of tin is best illustrated 
when it is used in the form of freshly cut shavings from a revolving 
ingot of the metal. Any operator can prepare his own shavings and 
have them fresh daily or hourly, if necessary, after the following 
method : Take an ordinary corundum wheel two inches in diameter 
and one-half inch in thickness, such as is used in the laboratory. Make 
a mould of this in sand or marble dust, then melt in a crucible or ladle 
enough pure tin to fill the mould. When it has cooled mount accurately 
upon the mandrel of the laboratory lathe, and from it, with a sharp car- 
penter's chisel, turn shavings of great tenuity. When freshly cut, and 
before oxidation of the surface has taken place by exposure to the atmo- 
sphere, it will be found that the tin coheres with the same readiness that 
pure gold does. Broken-down teeth can be built up by this method, or 
by means of it surfaces may be contoured as with gold. 

The plugging instruments best adapted for tin filling are those hav- 
ing shallow but well-defined serrations and points not too broad. As 
the marginal surface is approached broader points and condensers 
may be used, and the surface should be well burnished. The ope- 
rator must not lose sight of the fact that while tin possesses many 
desirable qualities and is easily manipulated, it lacks hardness and is 
not adapted to surfaces where great attrition occurs. Its chief value 
is found in its use upon surfaces concealed from view and shielded 
from wear, and in the temporary teeth, where its greatest value is 
manifest. 

Tin fillings should be finished with the same care as gold ones, and 
the same directions will apply in all particulars. 



FINISHING FILLINGS. 



297 



Finishing Fillings. 

Much of the beauty and utility of a filling is imparted to it in the 
finishing. It is not enough that it be well made, it must also be well 
finished if the best results are to be attained. 

All fillings should contain rather more gold than it is intended shall 
remain, and this for the purpose of dressing down to such lines as will 
be artistic and practical. 

Fillings that are not well condensed cannot be given a fine finish. 
Solidity of the surface is an essential quality. After the last piece of 
gold has been well condensed it is well to give the surface a thorough 
burnishing for the purpose of getting a compact surface as well as to 
insure perfect contact with the margins of the cavity. 

The simple fillings upon the occlusal surface of the bicuspids and 
molars are best dressed down with small finishing burs, as shoAvn in 

Fig. 261. These are fine cut and leave 
the gold with a better surface than when 
cavity burs are used for this purpose. 

The gold should be cut away until 
the margin of the cavity has been 
reached and until all overlapping of 
gold has been removed. The occlusion 
of the tooth of the opposite jaw should 
be noted, and, if it occludes unduly with 
the filling, enough should be taken from the surface of the gold to pre- 
vent it. When a uniform surface has been given to the gold, a suitable 

Fig. 262. 



Fig. 261. 




Plug finishing burs. 




Wood polishing points. 

wood point as shown in Fig. 262 should be mounted in an engine man- 
drel and dipped first in water and then in fine pumice powder and the 
surface nicely smoothed. A round-end burnisher may be used if the 
operator desires a polished surface, although it adds nothing to either 
the beauty or the utility of the filling. 

When fillings cover a larger portion of the occlusal surface the dress- 
ing down may be done with corundum points, which if kept wet will 
cut more rapidly than burs and cause less heating. These are shown in 
Fig. 263, and are of many patterns and admirably adapted to all parts 



298 



THE OPERATION OF FILLING CAVITIES. 



of the filling. Those made of fine corundum and shellac, or corundum 
and vulcanized rubber, are more desirable than the coarse ones, which 



Fig, 263. 




Corundum points. 



are liable to grind away the cavity margins because of the rapidity with 
which they cut. 



Fig. 264. 




Fig. 265. 




Felt polishing wheels. 
Fig. 266. 



Hindostan points. 

Fillings upon labial and buccal surfaces should be dressed down 
with fine corundum points or the Hindostan 
stones shown in Fig. 264 until the outline of 
the cavity has been reached. Any overlap- 
ping of the gold upon these surfaces gives a 
ragged appearance to the filling and detracts 
much from its beauty. Care should also be 
exercised in giving the filling the same degree 
of convexity that the tooth formerly had • in 
other words, the filling should accurately re- 
store the lost anatomical contour of the tooth. 

When sufficient gold has been removed the 
Surface should be nicely smoothed with re- 
volving wood points charged with pumice 
powder and water, or a paste made of pumice 
and glycerin, after which the final finish may 
be made with flour of pumice, chalk, or oxid 
of tin, used by means of a revolving disk or 
wheel of felt or soft rubber (Fig. 265). The 
soft rubber polishing cup of Dr. John B. 
Wood is a valuable aid in polishing the con- 
vex' surfaces of approximal fillings or those 
upon the cervical portion of labial cavities. 
It is shown in Fig. 266. As fillings upon the 
labial surface are more or less conspicuous at best, it is better not to 
give them a burnished surface. The dead or satin-like finish which is 
left by the flour of pumice is usually preferred. 




Dr. Wood's polishing cup. 



FINISHING FILLINGS. 



299 



Fillings upon approximal surfaces are more difficult to finish, and too 
great care cannot be bestowed upon them. An operator is often judged 
by the finish which he gives his approximal fillings, and justly so, as 
no class of fillings requires a higher degree of skill in the finishing. 

There is of necessity more or less overlapping of the gold in the 
insertion of a filling, and the removal of all excess is as important as 
any other part of the operation. For this purpose a great variety of 
instruments is supplied. Files and gold trimmers, as shown in Figs. 

Fig. 267. 




Ill 
Plug finishing files. 

267 and 268, are best adapted. The cervical border is one which 
should receive most careful attention. The gold should be filed and 
dressed down until the finest excavator or probe will not catch when 
drawn from the cervix toward the cutting edge. In addition to the 

Fig. 268. 




Curved finishing files. 

file and gold trimmer, strips of emery tape or sandpaper should be used 
until all margins are well defined. The operator should have at hand 
a great variety of these strips, some of extreme thinness and of various 
grits, of emery, of silex, and of buckhorn. 

When the filling has assumed the desired shape and all overlapping 
gold has been removed, the final finish should be given with linen or 



300 



THE OPERATION OF FILLING CAVITIES. 



cotton tape charged with pumice of exceeding fineness. If there are 
places where the tape cannot be made to reach, a soft-rubber wheel in 



Fig. 269. 




8 



Approxirnal trimmers. 

the handpiece of the engine and charged with the same powder may 
be used (Fig. 270). 

Fillings in the bicuspids and molars because of their inaccessible 
position are often most difficult to finish, and for this reason should 
receive unusual care. If a matrix has been used at the cervical border, 
and has been made to fit the tooth perfectly at or near the gum, it 
will be found that the finishing process has been simplified in a great 
measure, because there is less overlapping of the gold at this point. 

Fig. 270. 




Soft-rubber disks. 



The pointed files, right and left, as shown in Fig. 268, are admirably 
adapted to dressing away any overlapping of gold at the cervical border. 



Fig. 271. 




Sandpaper disks. 



With these and the trimmers shown in Fig. 269 the general outline 
of the filling may be obtained, after which the emery and corundum 
tape may be used and the filling polished after the same manner as 



REPAIRING FILLINGS. 301 

described above. Disks of sandpaper and emery cloth and finer ones 
charged with cuttlefish powder (Fig. 271) are exceedingly useful in 
shaping, and polishing the filling. Fig. 272 shows two forms of disk 
mandrels which may be satisfactorily used in carrying disks. 

Fig. 272. 




Morean-Maxfield disk mandrel. 



Many approximal fillings in the bicuspids and molars extend to the 
occlusal surface. When this is the case the operator should pay special 
heed to the occlusion of the opposing teeth. If left too full the con- 
stant touching of an opposing cusp may batter the filling, or, if not 
securely anchored, dislodge it. Overlapping gold is the rock of offence, 
and is the cause of many failures. A filling is not well finished until 
a delicate instrument can be passed from enamel surface to filling with- 
out catching. When this can be done, and dental floss is not frayed at 
the cervical margin, the inference is justified that no gold has been left 
overlapping. 

Repairing Fillings. 

Fillings somewhat defective are often susceptible of repair. The 
defect may sometimes be apparent in the finishing ; at other times it 
is the result of subsequent caries, and at still other times the result of a 
fracture of the tooth enamel alone: the border of the filling:. 

The nature of the defect and the condition of the remaining filling 
must be taken into consideration before an effort to repair is undertaken. 

When the defect is due to insufficient gold at any point in the filling 
more gold may be added. It is well to first cut out a portion of the 
filling, making a distinct cavity of retentive shape. Cohesive gold is 
usually best suited to the purpose ; crystal gold often serves well in 
the repair of such defects. 

If the filling has been thoroughly condensed and the mass is solid 
there is little difficulty in adding more gold to it, provided the surface 
be clean. If it has been wetted with saliva, the surface of the gold 
must be made not only dry but clean. It is well to wipe it with a 
pellet of cotton or paper saturated with alcohol or ether, after which 
the filling should be scraped with a suitable instrument. If the fill- 
ing be of considerable size and well anchored, shallow retaining pits 



302 THE OPERATION OF FILLING CAVITIES. 

may be drilled into it, which will make an additional hold for the 
gold which is to be added. Defects which arise from subsequent caries 
are perhaps more frequent in approximal surfaces at or near the cervical 
margin. These borders are vulnerable points for the recurrence of 
caries, and imperfect adaptation is not infrequently the determining 
cause of the beginning of such decay. 

To eifect a successful repair in such localities ample space should be 
obtained, especially so if the repair is to be made with gold. 

If the decay has not extended beneath the filling, and sufficient 
space has been obtained, there is no greater difficulty in making a suc- 
cessful repair than in filling a simple cavity similarly located. If the 
operator is skilled in the use of non-cohesive gold, he will do well to 
prepare his foil in the form of narrow tape, and work it into the cavity 
fold after fold, allowing the loops to extend somewhat above the walls 
of the cavity. When the cavity has been completely filled the protru- 
ding folds may be well condensed and the filling finished in the usual 
way ; or the repair may be made with cohesive gold, the first piece 
having been made fast in a groove or retaining pit. 

Such repairs are often required in the bicuspids and molars, and 
large fillings otherwise good are saved by a successful repair at the 
cervix. The plastics are sometimes indicated in this class of cases, 
provided they be not so near the anterior part of the mouth as to be 
unsightly. Gutta-percha often serves a good purpose here, but in some 
mouths undergoes decomposition and is less reliable than gold. The 
oxyphosphates are contraindicated because of their liability to wash 
away after a few months. Amalgams are more frequently used, and 
nearly always serve well when thus employed ; but unfortunately the 
contact with gold insures discoloration, and an unsightly filling is the 
result. Whenever gold and amalgam are brought in contact in the 
same tooth, if the surface of each is exposed to the fluids of the mouth, 
the amalgam is almost sure to turn quite black. The discoloration of 
the surface of the alloy does not lessen its value as a preserver of the 
tooth, but its unsightliness is often too great to be tolerated ; nevertheless, 
utility enters so largely into the equation that the operator feels justified 
in using the alloy, because with it he feels sure of making a better repair. 
After the alloy has hardened it should be nicely dressed down and all 
overlapping of the material at the gum margin removed, when it should 
be smoothed and polished with the same care that other fillings receive. 

Fracture of one or more of the cavity walls is a common accident, 
and one which may be repaired if the filling has been securely anchored 
in portions of the tooth not involved in the fracture. Such accidents 
sometimes befall bicuspids and molars, especially the bicuspids, where 
fillings have been inserted in each approximal surface, the two meeting 



REPAIRING FILLINGS. 303 

in the fissure upon the occlusal surface. The buccal wall is sometimes 
the one broken away, sometimes the lingual. In either case the ability 
to successfully repair depends upon the stability of the approximal 
fillings and the anchorage which can be obtained at the cervical wall 
and in the exposed fillings. To restore with gold a buccal cusp or the 
entire buccal surface of a bicuspid might necessitate a show of gold 
which would be objectionable ; and a better plan would be to engraft a 
porcelain facing or an entire porcelain crown ; whereas such a restora- 
tion on the lingual surface would not be open to the same objections. 
Cohesive gold alone is indicated for repairs of this kind. Watts' crystal 
gold when used in cases of this description has been most satisfactory. 

If the fracture extends above the margin of the gum the operation 
is much more difficult because of the danger from a flow of blood, and 
the additional difficulty of getting the rubber dam above the border 
of the fractured surface. This may be accomplished by filling for a 
few weeks with gutta-percha, when there will be recession of the gum 
caused by the pressure of the gutta-percha upon it. When a similar 
fracture occurs in a molar, if the fractured surface does not encroach 
upon the pulp, and will admit of drilling retaining pits without danger 
to the pulp, there is no difficulty in restoring the broken portion with 
cohesive gold. Mack's screws are sometimes indicated in cases of this 
kind, since strong anchorage can be secured in this way without much 
loss of tooth substance. 

Fracture of the incisal edge of the anterior teeth is often a serious 
accident, because of the difficulty of repair and the unsightly display 
of gold when it has been accomplished. 

Large fillings situated upon the approximal surfaces of the incisors 
but not extending to the cutting edge, yet near enough to weaken the 
enamel overhanging, are especially liable to need repairs. The corner 
of the tooth breaks away, leaving the surface of the gold exposed, and 
the only hold the filling has is at the cervical border and the slight 
undercut along the labial and lingual walls of the cavity. In order to 
secure retaining hold for additional gold the operator must be careful not 
to displace the original filling. Sometimes a retaining pit can be made 
laterally into the sound dentin, or, by cutting a little channel through to 
the lingual surface and then deepening the channel at its extremity with 
a round bur, a secure anchorage may be had for the fresh gold. 

Great care should be exercised in packing the gold lest by inadvert- 
ence the instrument should slip and push the original filling from its 
position. Fractured surfaces should receive prompt attention, for if left 
for a period of time disintegration of the dentin will set in and the 
caries may extend beneath the filling and thus jeopardize or ruin the 
most thorough work. 



304 THE OPERATION OF FILLING CAVITIES. 

Eroded Areas. 

There is a class of cavities which has not been specifically treated in 
the foregoing chapter, partly because the lesions under consideration 
cannot, strictly speaking, be classed under the head of carious cavities, 
and they are of such a peculiar formation that no definite rule can be 
laid down as to the best mode of treatment. If the eroded area be 
narrow and confined to the cervical border of the labial surface, and 
in a mouth in which the teeth are not conspicuous, a filling of gold 
may be employed ; but not infrequently the eroded area extends over 
a considerable portion of the labial surface, and in such cases a filling 
of gold would be so inharmonious that it should be avoided if possible. 
Hitherto the operator has had little choice of filling materials, and has 
often been compelled, against his better judgment, to employ gold in 
these cases. 

The zinc phosphates have been almost as inharmonious in color as 
the gold, and their durability has been so variable that they could not 
be regarded as permanent in character. The same may be said of gutta- 
percha. 

Happily, the progress which is being made in porcelain inlay ivork 
promises something both artistic and durable. It is quite possible, with 
the great variety of shades of porcelain now being furnished, to match 
the tint of the natural tooth, and if care be exercised in the selection of 
shades and the contour given to the inlay these eroded areas may be 
covered and the tooth made to assume almost as natural an appearance 
as before the disease had attacked the surface. (For a detailed descrip- 
tion of porcelain inlays the reader is referred to Chapter XV.) 



CHAPTER XIII. 

PLASTIC FILLING MATERIALS— THEIR PROPERTIES, USES, 
AND MANIPULATION. 

By Henry H. Burchard, M. D., D. D. S. 



The materials included in the heading of this chapter are — (1) 
Amalgam ; (2) Gutta-percha and its preparations ; (3) The basic zinc 
cements. 

History. — The introduction of the first member of the group was 
not prompted by any specific merit that it had been demonstrated to 
possess, but was due solely to its properties of easy introduction, com- 
paratively perfect sealing and prompt hardening, qualities which appar- 
ently recommended its wide and general use to those not possessing the 
requisite degree of skill for the successful manipulation of gold foil. 

Applied upon a basis of glaring empiricism, with an absence of 
technical skill, the material received the prompt and sustained con- 
demnation which its abuse had warranted. The steps and phases of 
this opposition of the trained and skilled against untrained and un- 
skilled operators may be read in the dental journals of from 1846 to 
1878 and even after. It was commonly known as the " amalgam war." 

The first dental amalgam was that of Taveau, called " Silver Paste." 
It was made of filings of coin silver (silver 9, copper 1), combined 
with sufficient mercury to make a plastic mass. It was presumably this 
alloy which was introduced into America by two charlatans named 
Crawcour, under the glittering title of " Royal Mineral Succedaneum." 
The discovery of the nature of the paste followed soon after its intro- 
duction, which was clearly prompted by the motives above stated. 
Thereupon followed a persistent and virulent attack upon the material 
and all who used it. Upon less than the merest shreds of evidence 
alleged cases of salivation and mercurial necrosis were recorded as due 
to the use of amalgam. 

That amalgam was still employed by the practitioners of France is 
evidenced by the presentation in 1849 of a formula for an amalgam 
alloy of pure tin and cadmium by Dr. Thomas Evans, an American 
dentist practising in Paris. An amalgam made from this alloy was 
found to shrink, and also to stain the dentin of teeth into whichlit had 
been introduced, owing to the formation of cadmium sulfid. It is note- 

20 305 



306 PLASTIC FILLING MATERIALS. 

worthy that Dr. Evans himself was the first to discover and make 
public the deficiencies of his amalgam. 

In America amalgam remained under a ban until Dr. Elisha Towns- 
end of Philadelphia, a practitioner of such great skill as to be safe from 
any imputation of lack of manipulative ability, introduced in 1855 an 
alloy of 44^ silver, 55 \ tin. The amalgam of this alloy received an 
endorsement and application based more upon the eminence of its 
author than upon the results of actual clinical tests, and a reaction 
occurred which brought amalgam again under general condemnation. 

What was known as the " new-departure corps " had its birth shortly 
after this time. This was composed of a limited number of practi- 
tioners and metallurgists, who were impressed by the fact that gold as a 
filling material was not the panacea of dental caries, and that by inves- 
tigation alone could the proper place of amalgam be found in the dental 
armamentarium. It is due to this group of investigators to state that 
the history of the rational employment of plastics is the history of the 
"new-departure corps." It was undoubtedly due to it that plastics 
have come to be regarded as substances having definite physical and 
chemical properties which fit them for application as restorative and 
therapeutic agents for the relief of clearly defined physical and patho- 
logical states. As the properties of these agents become better under- 
stood, their employment more closely follows what is known as rational 
therapeutics. 

The use of any or of all of these several materials is founded so 
entirely upon their individual properties that a discussion of these 
properties must precede and govern that of their methods of manipula- 
tion. 

Nature and Properties of Amalgam. 

An amalgam is a combination of one or more metals with mercury ; it 
is therefore any alloy into which mercury enters as a constituent. The 
word amalgam (Fr. amalgame) is derived from Gr. dpa, together, yajuecu, 
I marry ; or from d/ia and /m^ay/jta, from tmXdoaco, I soften — because 
of the softness and fusibility which mercury confers upon alloys. 

It is to be understood that amalgams are classified as alloys, and may 
be therefore members of any of Matthiesseir's groups as follows : A chemi- 
cal compound in which the affinities are exactly satisfied ; one in which 
there is unstable chemical equilibrium ; a sub-chemical compound, or 
a mechanical mixture — although this latter is rare, as mercury exhibits 
some degree of affinity for all metals. 

There are two possible ways in which mercury brings about the 
solution of other metals : First, by a chemical affinity for the metals ; 
second, by lowering the melting-point of the solid metal, forming an 



NATURE AND PROPERTIES OF AMALGAM. 307 

alloy whose melting-point is higher than that of a mean of its constitu- 
ents. The former is the explanation more in accord with the observed 
phenomena relative to the combination. 

Physical Properties of Amalgams. — As a class amalgams have defi- 
nite physical properties. First, that of hardening from a previous 
plastic condition; and nearly all of them for some time subsequent to 
apparent hardening undergo change of volume and of form. The 
change of volume may be either contraction or expansion. 

Contraction and Expansion. — In contraction the mass tends to 
assume the form shown in Fig. 273. 

It has been shown by Dr. Black 1 that FlG - 273 - 

the extent of this contraction is due to 
several factors : 

1. To the composition of the pri- 
mary alloy. All other things being 
equal, an alloy of 65 per cent, silver, 
35 per cent, tin, represents about the 
fixed point where there is a minimum _. ~?~ ^ ~L . , 

t^ ""v. Diagram of amalgam shrinkage. 

of shrinkage. As a class, alloys con- 
taining less than 65 per cent, silver make amalgams which contract ; 
those containing more than 65 per cent, silver make expanding 
amalgams. 

2. To the amount of mercury used in amalgamation. There appears to 
be a definite percentage of mercury which produces the greatest strength 
of an amalgam mass ; moreover, the percentage which produces the 
maximum strength increases the shrinkage of the shrinking alloys and 
increases the expansion of the expanding alloys. Surplus mercury in 
the amalgam mass can reduce neither the expansion nor contraction 
of the amalgam mass. While an excess or deficiency of mercury in- 
creases the shrinkage or expansion of an amalgam (according as the 
percentage of silver is 65 — or 65 +), these volume changes cannot be 
overcome by the percentage of mercury. An excess or deficiency of 
mercury weakens an amalgam. It would appear that the conditions 
which bring about the most perfect union of the metals produce the 
greatest changes of bulk in those alloys in which changes of bulk occur. 
An alloy the amalgam of which neither shrinks nor expands cannot be 
made to do so by changes in the amount of mercury employed. 

3. A strong controlling factor has been found to be the evenness 
of distribution of mercury and alloy throughout the amalgam mass. 
An increase of the ratio of silver above 70 per cent, is followed by an 
enormous expansion of the hardening mass. It had always been noted 
that the amalgam made of a coin-silver alloy bulged from the walls of 

1 Dental Cosmos, 1895, vol. xxvii. p. 637. 



308 PLASTIC FILLING MATERIALS. 

a cavity inclosing it. This alloy contains, as stated, 90 per cent, of sil- 
ver. The appearance of an expanded amalgam is similar to that of ice 
at the mouth of an iron tube in which the water has been frozen. 

Copper amalgam is the only alloy tested by Dr. Black which under- 
went no change of form in hardening. 

" Flow " of Amalgam. — A property attributed to certain amalgams, 
that of spheroiding, has been shown by Dr. Black to be without exist- 
ence. The bulging of amalgams from the orifices of cavities was held 
to be due to the tendency of the mass to assume a spheroidal form, hence 
the term spheroiding. Tests showed the appearance to be delusive, the 
phenomenon being due to expansion and not to a spheroidal tendency. 
In addition to the properties of contraction and expansion the same 
investigator has discovered the property, hitherto unsuspected in amal- 
gams, that of flow. The property of flow — i. e. change of mass form, from 
molecular motion under stress— had been observed in the majority of 
metals, but as found in amalgams it has a unique expression. Instead 
of being limited to a definite degree, proportioned by the stress applied, 
it has been found that amalgams yield repeatedly to the same amount of 
stress when applied at intervals, as in mastication, or yield continuously 
when the stress is constant. The process appears to be without limita- 
tions. It is at zero in copper amalgams ; next less in amount with alloys 
containing 55-60 per cent, of silver with 5 per cent, copper and the 
remainder tin. It will be readily seen that this property exercises a 
great influence upon the integrity and adaptation of an amalgam filling. 

The notes quoted from Dr. Black were compiled from studies made 
of amalgams whose exact chemical composition had not been actually 
tested by the investigator. Later experiments * made with alloys pre- 
pared with the utmost care and exactitude by the investigator himself, 
gave widely different results (particularly as to the effect of adding a 
third or fourth metal to the basal alloy) in the direction of both flow 
and shrinkage. The first series of experiments which appeared to show 
an enormous increase of shrinkage and flow together with a lessening of 
edge strength, by the addition of a third or fourth metal (except copper, 
which the latest experiments still show to lessen flow and increase 
rigidity) were not confirmed when Dr. Black experimented with alloys 
made by himself, and an additional and unsuspected factor was taken 
into consideration, viz. the influence of heat upon the alloy. 

It has been noted by Dr. J. Foster Flagg 2 that alloys which were 
freshly cut possessed working properties different from the same alloys 
when " old cut," or when aged. Dr. Black's observations appeared 
to confirm this, and his later experiments were directed toward deter- 
mining the cause underlying the change. Motion, which was said to 

1 Dental Cosmos, December, 1896. 2 Plastics and Plastic Fillings. 



NATURE AND PROPERTIES OF AMALGAM. 



309 



bring about the change, was found to have no influence. After exhaus- 
tive and conclusive experiments it was ascertained that the change was 
due to a molecular alteration of the cut alloy, through a process of an- 
nealing or " tempering " — i. e. heat was the agent producing the change. 
The degrees of heat applied ranged from 130° to 212° F. 

It was found that the amount of time during which an alloy was 
subjected to the action of heat governed the extent of tempering ; for 
example, alloy subjected to a temperature of 130° for a given period, 
had the amount of amalgam expansion reduced a given amount; if 
the heat were maintained for a longer period the expansion was corre- 
spondingly decreased. Each formula has its zero point beyond which 
tempering has no effect. 

In general terms, it was found that alloys in amalgams which 
expanded in hardening had the extent of expansion reduced by anneal- 
ing ; those which contracted had the contraction increased. 

Alloys which were without alteration of volume unannealed, shrank 
when annealed. 

The following tables will show the extent of change produced by 
annealing. It will be noted that the alloy of 72.5 silver, 27.5 tin, ex- 
hibits the minimum contraction after annealing. It will also be observed 
that less mercury is required to effect amalgamation in the annealed 
alloy. 1 Amalgams made from annealed alloys have both their flow and 
crushing stress slightly increased. 



I. Exhibit of Unmodified Silver-Tin Alloys. 2 



Formula. 


















How prepared. 


Per cent, of 
mercury. 


Shrinkage. 


Expansion. 


Flow. 


Crushing 






stress. 


Silver. 


Tin. 














40 


60 


Fresh -cut. 


45.78 


6 


7 


40.15 


178 


40 


60 


Annealed. 


34.14 


9 


3 


44.60 


186 


45 


55 


Fresh-cut. 


49.52 


4 


8 


25.46 


188 


45 


55 


Annealed. 


32.13 


11 


1 


28.57 


222 


50 


50 


Fresh-cut. 


51.18 


2 


2 


22.16 


232 


50 


50 


Annealed. 


37.58 


17 


1 


21.03 


245 


55 


45 


Fresh-cut. 


51.62 


2 


2 


19.66 


245 


55 


45 


Annealed. 


40.11 


18 





17.53 


276 


60 


40 


Fresh-cut. 


52.00 


1 





9.06 


239 


60 


40 


Annealed. 


39.80 


17 





14.10 


297 


65 


35 


Fresh-cut. 


52.00 





1 


3.67 


290 


65 


35 


Annealed. 


33.00 


10 





5.00 


335 


70 


30 


Fresh-cut. 


55.00 





14 


3.45 


316 


70 


30 


Annealed. 


40.00 


7 





4.67 


375 


72.5 


27.5 


Fresh-cut. 


55.00 





42 


3.92 


275 


72.5 


27.5 


Annealed. 


45.00 


3 





3.76 


362 


75 


25 


Fresh -cut. 


55.00 





60 


5.64 


258 


75 


25 


Annealed. 


50.00 





6 


5.40 


300 



2 For a full exhibit of this stupendous work of Dr. Black's, the reader is referred 
to his contributions in the Dental Cosmos for 1895 and 1896. 
2 Black, Dental Cosmos, 1896, p. 982. 



310 



PLASTIC FILLING MATERIALS. 





II 


. Exhibit of Modified Silver- Tin 


Alloys. 1 






Formula. 




















How pre- 
pared. 

Fresh-cut. 


Per cent, 
ofmercury. 


Shrinkage. 


Expansion. 


Flow. 


Crushing 

stress. 


Modifying 
metal. 


Silver. 


Tin. 




65 


35 


52.33 





1 


3.67 


290 




65 


35 


Annealed. 


33.00 


10 





5.00 


335 




66.75 


33.25 


Fresh-cut. 


51.52 





4 


3.35 


329 




66.75 


33.25 


Annealed. 


33.53 


7 





5.06 


380 


Gold 5. 


61.75 


33.25 


Fresh -cut. 


47.56 





1 


4.62 


330 


Gold 5. 


61.75 


33.25 


Annealed. 


30.35 


7 





6.07 


395 


Platinum 5. 


61.75 


33.25 


Fresh-cut. 


51.87 





9 


9.68 


273 


Platinum 5. 


61.75 


33.25 


Annealed. 


37.33 


7 





8.20 


352 


Copper 5. 


61.75 


33.25 


Fresh-cut. 


53.65 





23 


2.38 


343 


Copper 5. 


61.75 


33.25 


Annealed. 


35.60 


5 





3.50 


416 


Zinc 5. 


61.75 


33.25 


Fresh-cut. 


56.65 





68 


1.83 


290 


Zinc 5. 


61.75 


33.25 


Annealed. 


40.65 





9 


2.07 


345 


Bismuth 5. 


61.75 


33.25 


Fresh-cut. 


46.26 








4.78 


288 


Bismuth 5. 


61.75 


33.25 


Annealed. 


23.67 


6 





5.58 


308 


Cadmium 5. 


61.75 


33.25 


Fresh-cut. 


57.57 


• 


100 


6.40 


225 


Cadmium 5. 


61.75 


33.25 


Annealed. 


47.25 





5 


3.54 


290 


Lead 5. 


61.75 


33.25 


Fresh-cut. 


44.17 





1 


4.88 


290 


Lead 5. 


61.75 


33.25 


Annealed. 


32.76 


10 





7.18 


276 


Aluminum 5. 


61.75 


33.25 


Fresh-cut. 


65.00 





445 






Aluminum 1. 


64.5 


34.5 


Fresh-cut. 


46.98 





166 


12.60 


198 


Aluminum 1. 


64.5 


34.5 


Annealed. 


38.26 





48 


17.90 


213 



Edge Strength. — What is termed the edge strength of an amal- 
gam is the degree of resistance an edge or angle of an amalgam mass 
offers to force which tends to fracture it. 

Amalgams have heretofore been regarded as rigid crystalline masses, 
utterly devoid of malleability. The discovery of the existence of flow 
at once modifies all previous conceptions and data regarding edge 
strength, for it is evident that a corner or angle might not fracture and 
yet might flow under the stress of the impact of mastication, whereupon 
edge strength might be said to be great, and in reality be but slight. 
In view of the existence of the property of flow, edge strength must be 
measured as rigidity, the antithesis of flow, and a high crushing stress. 

It has been shown that contraction or expansion, and flow, are the 
influences which would disturb the maintenance of size and form of 
an amalgam filling ; therefore, a minimum of shrinkage and flow are 
the primary considerations in a satisfactory dental amalgam. 

Color. — One of the serious drawbacks to the wide employment of 
amalgam has been its objectionable color, both in its original state and 
furthermore when it has suffered discoloration through the formation of 
ox ids or sulfids upon its surface. The silvery white of amalgam in its 
most acceptable condition is not so harmonious a color as the yellow of 
gold, which fact has led first to the restriction of the use of amalgams 
to such spaces as are not readily visible, where its original and subse- 
quently its altered color could not be a strong objection ; and, next, 

1 Black, Dental Cosmos, 1896, p. 987. 



NATURE AND PROPERTIES OF AMALGAM. 



311 



has prompted a modification of the silver-tin formulae with the object 
of maintaining their original color. 

The discolorations are not alone upon the external surfaces of fill- 
ings, but frequently (and most frequently in improperly prepared and 
filled cavities) the discoloration affects the dentinal walls bounding the 
cavity (see Fig. 274). 

Fig. 274. 




Staining of tooth structure with amalgam (Bodecker) : e, enamel ; D, D, dentin ; B, border of cav- 
ity ; s, solidified dentin along the border of the cavity ; k, reticulum brought forth by the 
amalgam, (x 500.) 

As shown in the illustration the discoloration may be deep. This 
danger is increased by leakage, when putrefaction of the protoplasmic 
contents of the dentinal tubuli or decomposing albuminous substances 
generate H 2 S, and metallic sulfids are formed in marked quantities. 



312 PLASTIC FILLING MATERIALS. 

This danger of dentinal discoloration is guarded against by interposing 
a barrier between the cavity walls and the amalgam prior to the inser- 
tion of the latter. The influence of individual metals upon color will 
be discussed later. 

Thermal and Chemical Relations. — As a conductor of thermal in- 
fluence, amalgam is midway between gold and the basic zinc cements. 

As to the actual effects upon the vital tissues of dentin, it has 
never been demonstrated that amalgam exercises any specific influence, 
except that cadmium appears to cause, through the cadmium sulfid 
formed, a degenerative influence (Flagg), and copper has antiseptic 
properties (Miller, Fletcher). 

Chemically the dental amalgams are, to all intents and purposes, 
insoluble in the fluids of the mouth, the common solvent found in the 
oral cavity, lactic acid, affecting them but little. 

Classification of Amalgams. — Amalgams are divided into binary, 
ternary, quaternary, and so on, according to the number of constituent 
metals. The only binary amalgams employed in dentistry are those of 
copper and of palladium. 

Binary Amalgams. — Copper amalgam is made by adding freshly 
precipitated and washed metallic copper to an excess of mercury ; when 
solution is complete the surplus mercury is expressed through chamois. 
The plastic residuum is then packed into moulds to make small tablets 
of the usual form in which it is dispensed. 

A better method, which yields a product of greater purity, is to pre- 
cipitate the copper directly into the mercury by electrolytic process. 
This may be done conveniently by pouring a quantity of mercury into 
a suitable glass vessel — a small battery jar, for example — and suspend- 
ing a thick plate of copper, by means of a wooden support, some dis- 
tance above the surface of the mercury. A saturated solution of 
cupric sulfate is then poured into the jar until the copper plate is com- 
pletely submerged. The cathode pole of a battery or other source of 
electrical current is then connected with the layer of mercury, and the 
anode with the copper plate. All that portion of the cathode electrode 
in contact with the cupric sulfate solution should be insulated with gutta- 
percha, and only the point which is in contact with the mercury left 
exposed. The passage of the current causes solution of the copper 
from the anode and deposits it in the mercury continuously as long as 
the foregoing conditions are maintained. The precipitation should be 
continued until the mercury is saturated, which will be evidenced by 
the appearance of the characteristic red color of the excess of copper at 
the cathode pole. When the saturation point has been fully reached 
the mass should be washed, first in dilute hydrochloric acid and then in 
water, dried and compressed as is usual with this amalgam when pre- 



NATURE AND PROPERTIES OF AMALGAM. 313 

pared by the ordinary processes. This method was suggested to the 
writer by Dr. E. C. Kirk. 

In its typical form and condition, copper amalgam, when made 
plastic by heat, may be packed into matrices, such as cavities in 
teeth, where it sets quickly, undergoes no change of volume or form, 
and is devoid of flow. Therefore a cavity which has been sealed by 
it remains sealed. Upon its outer surface a coating of black sulfid 
quickly forms, which remains but does not penetrate the tooth struc- 
ture. The dentinal walls are commonly stained green through the 
absorption of the metallic salts. 

In improperly prepared specimens there is not a perfect chemical 
union between the metallic mercury and the copper. The presence in a 
filling mass of oxids of either of these metals establishes local electrolytic 
conditions which prevent the formation of the black sulfid coating and 
bring about the gradual dissolution of the amalgam mass. To recapitu- 
late : Copper amalgam is physically unchangeable as a filling material ; 
it brings about very offensive discoloration both of the dentin and of 
its own surface ; it is antiseptic. 

The second binary amalgam is that of palladium. Palladium is 
precipitated from a solution of its chlorid by iron or zinc, washed in 
nitric acid, and dried. To the precipitated metal, mercury is added, 
the combination being attended by the evolution of much heat (i. e. is 
an active chemical union). If an excess of mercury has not been used 
the amalgam sets quickly, does not alter in form, 1 and becomes black 
upon the surface, 2 but does not discolor the dentin. The addition of 
an excess of mercury retards the setting, and produces an inferior filling. 

Ternary Amalgams. — The base of all ternary amalgams is the 
alloy of silver and tin. The first of these was the alloy of Townsend, 
44^ per cent, silver, 55-j per cent. tin. From this point the investi- 
gations and experiments radiated — it being found after many years of 
clinical testing that those alloys containing more than 50 per cent, of 
silver gave the best results. 

The formula given by Dr. J. Foster Flagg as affording the most 
stable alloy for amalgam — 60 silver, 35 tin, and 5 copper — Avas found 
by Dr. Black to be that giving the highest degrees of resistance to 
change of form, to flow, and to crushing. In view of Dr. Black's 
researches into the effects of annealing alloys it is evident that the 
ternary amalgam of the future will have a composition closely approxi- 
mating 72.5 per cent, silver, 27.5 per cent. tin. 

The binary alloys of tin and silver form the basis of all of the 
quaternary amalgams used in dentistry. 

1 Tomes, Trans. Odontological Society of Great Britain, 1872. 

2 Bogue, Dental Cosmos, 1884. 



314 PLASTIC FILLING MATERIALS. 

Quaternary Amalgams. — The metal additional to the basal alloy 
is added for the purpose of modifying the color or increasing the edge 
strength of the amalgam. The addition of copper 5 per cent, to an 
alloy containing over 60 per cent, silver increases the crushing stress 
and lessens both flow and contraction. The alloy is white when fresh, 
but in the presence of sulfur compounds discolors. 

The addition of gold (5 per cent.), as clinical records testify, aids in 
maintaining the color of the filling. It lessens shrinkage slightly (com- 
pare this and following statements with table No. II.), and appears to 
have little or no influence upon flow and crushing stress. The addition 
of platinum causes dark fillings and notably increases the flow ; the 
setting is slowed. 

The addition of zinc increases rigidity ; the amalgams expand for 
long periods after apparent hardening ; the crushing stress is moderately 
high — a direct contradiction of statements of several previous ob- 
servers. 1 

Additions of bismuth, cadmium, lead and aluminum were made to 
the basal alloy, but all of them exhibited properties which exclude 
them from introduction into dental amalgam. 

Dr. Black 2 states that " alloys containing 5 per cent, of aluminum 
have their setting attended by the evolution of much heat ; an enormous 
expansion of the mass occurs ; the instruments used in packing are oxi- 
dized, and a distinct crackling of gas-disengagement is heard." " The 
formation of aluminum amalgam is characterized by an exhibition of 
the affinity of aluminum for oxygen. Aluminum oxid is doubtless 
formed, which increases the volume of the amalgam mass." 

"Washing" of Amalgams.- — Alloys which have been cut for some 
time, and mercury the purity of which is questionable, are found to be 
coated with oxids of the metals — in the case of mercury, with the oxids 
of contaminating metals. The advisability of washing the amalgam 
mass in some solvent which will remove the oxids is a mooted question. 
It has been stated that the washing of an amalgam mass increases its 
shrinkage (Flagg). On the other hand it has been observed that 
washed amalgams retain their color better. It is difficult to see how 
the washing could affect the integrity of the set mass unless oxidizing 
substances were left in it ; and this is clearly contraindicated by the 
maintenance of color in washed amalgam. The writer prefers wash- 
ing the plastic mass in chloroform prior to expressing the surplus of 
mercury. 

1 It is to be recalled in this connection that Dr. Black' s measurements are made with 
instruments of unequalled accuracy, those of previous observers with comparatively crude 
instruments. 

2 Private communication. 



USE OF AMALGAM. 315 



Use of Amalgam. 



It is to be understood that amalgam is to be employed only in those 
conditions and situations which clearly indicate it as the proper mate- 
rial. As a general rule, it is excluded from the ten anterior teeth of 
each jaw, although this rule is open to exceptions. Its anterior limit 
of application is usually regarded as the distal surface of the first bicus- 
pid. Its more general employment has been greatly reduced in many 
places since the introduction of what are known as combination fillings 
(see Chapter XIV.), and by improvement in the forms and character of 
artificial crowns. 

The first class of cavities to which amalgam is applied are those 
which extend beneath the gum margin ; the second, buccal cavities ; the 
third, compound cavities ; the fourth, approximal cavities ; the fifth, 
cavities upon the masticating faces of the teeth. These are the classes 
in which gold is most difficult of introduction and of proper shaping 
and finishing, in the order named. Amalgam should rarely or never be 
packed against dentinal or enamel walls without the interposition of a 
layer which will prevent either the discoloration of the dentin or the 
bluish appearance noted when amalgam underlies enamel. 

The shaping of cavities for the reception of amalgam fillings (see 
Chapter VIII.) should be done with such care as will give assurance 
of the permanent retention of the filling and the perfect sterilization of 
- the dentin before and during its introduction. 

The separation of the teeth, removal of gum overhanging cavity 
margins, and breaking down of frail enamel walls by means of chisels, 
precede the filling. 

The rubber dam is to be adjusted where and when possible, with such 
care that an exclusion of the fluids of the mouth is assured during the 
shaping, sterilizing, and filling of the cavity. As Dr. Black has shown, 1 
much of the permanency of form of an amalgam mass depends upon 
the even distribution of the constituents ; it is evident that every aid to 
this end should be utilized, an important one being that the mass should 
be packed into a cavity having but one orifice, that for the introduction 
of the filling. 

With the data relative to dental amalgams which have been given, 
it is evident that a dental amalgam mass is by no means simple, but is 
a very complex body. If sufficient mercury has been used to effect 
solution of the alloy particles the mass will consist, first, of a quantity 
of a chemical amalgam — i. e. one in which the metals are united in 
atomic ratios — this being surrounded by one or more other distinct 

1 Dental Cosmos, 1895, vol. xxxvii. p. 553. 



316 



PLASTIC FILLING MATERIALS. 



amalgams, each having its own time of setting and rate of contraction. 
If only enough mercury has been used to make a creaky mass the sur- 
faces of each alloy particle are covered by an amalgam of indefinite 
composition which acts as a cement binding the particles together. In 
this line the same experimenter has shown that mixing the alloy and 
mercury in a mortar by means of a pestle, wringing the surplus mer- 
curial solvent from the mass by means of heavy pliers, and packing the 
filling with steel burnishers are all influences which lessen the strength 
of the completed filling. 

The conditions are now a prepared and sterilized cavity ; any miss- 
ing wall required to give four sides has been replaced by a properly 
adjusted matrix (see Figs. 255, 256, Chapter XII.). 






Fig. 275. 






Dr. Herbst's matrix. 

Matrices. — Matrices may be readily and quickly formed by cut- 
ting strips from a sheet of very thin steel which has been annealed 

Fig. 276. 




Fig. 277. 




Herbst pliers. 



and polished. By means of contouring pliers the matrix is given 
the correct contour, then wedged or tied into place. They must 



USE OF AMALGAM. 



317 



be so adjusted that they are immovably held during the filling ope- 
ration. 

A rapid method of forming a matrix is that of Dr. AVilhelm Herbst : 
A strip of German silver No. 33, wide enough to extend from the 
cervical margin of a cavity to its mouth, and long enough to more than 
embrace the tooth, is passed around the tooth (see Fig. 275) ; the strip 
is caught near its extremities by a pair of Herbst pliers (Figs. 276, 
277) and drawn taut; the pliers pinch the metal into close adaptation 
to the tooth walls. Held by the pliers the matrix is withdrawn, the 
line of junction touched with zinc chlorid solution, and soldered over 
an alcohol or Bunsen flame with soft solder. The matrix is replaced 
upon the tooth, the rubber dam applied, and the matrix pressed 
against the cervical margin of the cavity by means of a wooden 
wedge. 

The matrices of Guilford and those of Brophy (Figs. 253, 254, 
Chapter XII.) are operated upon a common principle ; the band which 
most nearly fits the periphery of the tooth is adapted, then drawn 
into close apposition with the tooth by means of the screw appli- 
ances. 

The matrix of Woodward is one of the most convenient. Its mode 
of application is shown in Fig. 256, Chapter XII. 

The Miller matrix (Fig. 278) is useful and adapted for the class 
of cavities shown in Fig. 279, as held in contact with cervical mar- 



Fig. 278. 




The Miller matrices. 




gins through the action of the duplex spring leaflets. Fig. 279. 

When necessary a wooden wedge is forced between 
the leaflets. 

(For other forms and applications of matrices see 
Chapter XII.) 

Mixing the Amalgam. — It is usually recom- Oilier matrix adjusted. 
mended that the proportion of mercury and alloy be determined by 
weight. An amount of alloy is first weighed, then weighed additions 
of mercury are added to it sufficient to make a plastic mass, when the 
two are to be mixed together; the relative amounts of mercury and 
alloy are to be gauged and recorded for each formula of alloy. With 
the " submarine " alloy of Flagg— 60 silver, 35 tin, and 5 copper— the 



318 



PLASTIC FILLING MATERIALS. 



ratio is equal parts by weight of filings and mer- 
cury. When a mortar is used for making the amal- 
gam, one of glass and having a glass pestle (see 
Figs. 280, 281) is to be preferred. Mixing in the 
palm of the hand is a dirty process, the hand and 
fingers becoming much discolored by the metallic 
oxids. 

Fig, 280. 



Fig. 281. 





Glass mortar. 



Glass pestle. 



A rubber mortar (Fig. 282) to be received in the palm of the hand 
has been devised by Dr. Genese. In view of deductions from Dr. 



Fig. 282. 




Dr. Genese's rubber mortar. 

Black's experiments this latter method of mixing is regarded as usually 
the preferable one. 

The filings are placed in the receptacle, the mercury is added, and 
the mass is triturated — if in a mortar, by the pestle, if in the rubber 
basin, by the forefinger guarded by a rubber finger-stall. When the 



USE OF AMALGAM. 



319 



amalgamation appears to be complete the mass is transferred to the 
hand and kneaded, then pressed into a ball. It is next enclosed in 
stout muslin, or China silk as recommended by Dr. C. E. Kells, Jr., 
and the surplus mercury expressed by wringing ; when no more mer- 
curv appears through the muslin, the button is removed : it should break 
with a clean, white fracture surface. 

Another method of mixing the filings and mercury is that of Fletcher. 
Filings and mercury are placed in a long glass tube which is shaken vio- 
lently until amalgamation is complete. 

The Packing- Operation. — Several devices have been invented for 
the purpose of carrying the amalgam to the tooth cavity, one of the 

Fig. 283. 



most simple being shown in Fig. 283, and another in Fig. 284. An- 
other excellent instrument is shown in Fig. 285, one end having ser- 

Fig. 284. 




rated points which engage the soft amalgam, the other a plugger 
head. 

Numerous methods have been advanced and advocated for the pack- 
ing operation. The one commonly followed is that of burnishing the 
amalgam. This has been shown by Dr. Black to weaken the mass. A 
small piece, rarely more than a cube of -|- in. side, is carried to the deep- 
est and most inaccessible recess of the cavity and pressed against its 
walls by tapping, burnishing, or uniform pressure. Dr. Flagg's method 
is by tapping. Each successive piece of amalgam is tapped upon by the 
packing instruments until it combines with its predecessor and is per- 
fectly adapted to the cavity walls. The set of instruments shown in 
Fig. 286 are those by which this process is accomplished — Nos. 30-34 
being packing instruments, while the others are shapers. 



320 



PLASTIC FILLING MATERIALS. 



A convenient and effective set of instruments for accomplishing the 
packing are shown in Figs. 287-289. 





30 31 32 33 34 35 36 37 38 39 40 

Dr. J. Foster Flagg's amalgam and zinc filling instruments. 

Dr. W. G. A. Bon will has advised a method which accomplishes the 
removal of surplus mercury and the even distribution of the mass, 

Fig. 287. 




Fig. 288. 




Woodson's double-end amalgam instruments 



during the progress of the filling. Small squares of folded bibulous 
paper are caught in the jaws of pliers and laid upon the amalgam, 
when the exertion of pressure by means of amalgam pluggers or 
pliers forces out the surplus solvent and it is wiped away with the 
paper. The same end is also accomplished by the use of bulbous 
points of soft rubber. 

When through either method the cavity is more than half full, the 
remainder of the amalgam mass is wrung out to express more mercury, 
and the packing is resumed until the cavity is more than full. 

At the later stages of the filling the process of wafering is usually 



USE OF AMALGAM. 



321 



Fig. 290. 



followed. By means of chamois and heavy pliers (Figs. 290, 291) the 
amalgam mass remaining is compressed into 
a wafer, driving the surplus mercury through 
the pores of the chamois. The amalgam is 
put in a piece of chamois, and the chamois 
sack A is entered between the beaks b and 
c (the latter a roller) ; closing the handles 
of the instrument progressively squeezes out 
the mercury till any desired degree of dryness 
is attained. When the amalgam is squeezed 
to the requirements of the operator, the han- 
dles are released, and the spring opens the ap- 
pliance. The action is analogous to the finger 
and thumb movement in common use, but is 
much more powerful, and therefore more cer- 
tain and more uniform. Small sections of the 
wafer are laid upon the half-completed filling 
and tapped into a union with it. The cavity 
is more than filled, and at the completion of 
the packing the amalgam should cut as though 
nearly set. 

Another and excellent method where applicable is to shape small 
pieces of half-vulcanized rubber and cement them upon broken excava- 




Mercury expresser. 



Fig. 291. 




Flagg's wafering pliers. 

tors, and use them as pluggers during the later stages of the filling. 
The fluid cementing amalgam will have its surplus mercury expressed 
about the sides of the plugger. 

Still another method is to fill the cavity more than half full, then 
cut away the softened portion, and complete the filling with drier amal- 
gam. Fillings the initial portions of which have been introduced com- 
paratively dry are more homogeneous and are less likely to discolor 
and crevice than when more fluid amalgam has been used to begin the 



322 PLASTIC FILLING MATERIALS. 

filling. An examination of an amalgam filling immediately after com- 
pletion will show the marginal portions to contain the softer amalgam, 
the harder being in the more central parts. 

The too common practice of placing in the prepared cavity sufficient 
amalgam in one mass to nearly or quite half fill it, is faulty. By no 
means can this method secure the accuracy of adaptation of filling 
material to cavity walls which is demanded of a correct filling. 

At the completion of the packing operation, unless the filling has 
been finished by wafering, the surface will be found still soft. It has 
been recommended l that small pieces of annealed No. 1 gold foil be 
burnished over the surface of the amalgam, until no more gold can be 
amalgamated by this means, when the filling will be found quite hard. 
The indefinite cementing amalgam has combined with the gold, for 
which mercury has a strong affinity, and formed a distinct amalgam 
upon the surface of the filling proper. As amalgams of gold are com- 
paratively soft, it is advisable to first fill the cavity more than full, apply 
the gold foil, then scrape the filling down to the cavity margins. Dr. 
Rhein's procedure is to fill the cavity with plastic amalgam and rub on 
the pieces of gold until no more gold is amalgamated. This gold amal- 
gam is permitted to remain. The surplus of mercury may also be con- 
veniently removed by absorbing it from the surface of the filling by 
pieces of sponge or crystal mat gold. 

An amalgam filling should be hard enough to resist cutting before 
the rubber dam is removed. 

In those situations where the rubber dam cannot be successfully 
employed, it is the accepted practice to prepare the cavity, sterilize it, 
when access is difficult sealing a germicide in the cavity for a day; next 
adjust a napkin, and having mixed a submarine amalgam (one contain- 
ing copper and a high percentage of silver), the cavity is dried as well 
as possible ; a piece of the amalgam is then carried to the deepest recess 
of the cavity and quickly and forcibly compressed with a mass of 
bibulous paper. Another piece of amalgam is added and compressed, 
driving the surplus mercury from the amalgam. While the napkin is 
in position, a mass of temporary stopping (which see) is softened and 
placed in the remainder of the cavity. A knife blade passed over the 
edges of the amalgam will remove overhanging portions. At a subse- 
quent visit, the rubber dam is adjusted, the temporary stopping is 
removed, and the filling completed with amalgam. 

If the operator prefer, the rubber dam may be adjusted at once and 
the filling completed at one sitting ; the former method is, however, pre- 
ferable, as the cervical portion of the filling may be perfectly finished, 
and not be in danger of displacement, while the second section is packed. 
1 Ottolengui's Methods of Filling Teeth, ''Method of M. L. Rhein." 



USE OF AMALGAM. 323 

In cavities extending beneath the gum, and opening broadly upon a 
surface of a tooth where discoloration would be highly objectionable, 
the cervical half of the filling is made of a submarine amalgam and is 
completed with an amalgam containing gold, which will retain a better 
color. Should the external face of the filling be readily visible and not 
subjected to the stress of mastication, its outer surface is made of a 
wafer of an amalgam containing zinc, known as a facing amalgam. 
Copper amalgam is used, when used at all (and that is but seldom), 
upon the distal and buccal walls of third molars, in cavities extending 
under the gum line, which are difficult of access and to sterilize, and 
which cannot be properly dried. 

A cavity is prepared which need be but slightly undercut. A pellet 
of the copper amalgam is placed in an iron spoon (Fig. 292) held above 

Fig. 292. 




Heating spoon for copper amalgam. 

a Bunsen flame until globules of mercury appear upon its surface, when 
it is quickly crushed in a mortar and pounded until made into a paste. 
There can be no objection to washing the soft mass in aqua ammonia to 
dissolve and remove oxids which later form discoloring salts, and thus 
permit a chemical union of the metals which would be prevented by 
their presence. A napkin, or always when possible the rubber dam, 
is adjusted, and the filling inserted in sections. At the end of the oper- 
ation the filling should be firmly compressed with a broad -bladed spatula. 

In by far the greater number of cases in which amalgam was at one 
time used alone, it is now the accepted practice to place a lining of a 
zinc cement, and add the amalgam as a resistant and insoluble covering. 

In cavities which approach the pulp the same precautions are taken 
for the prevention of thermal shock as with gold. 

The most difficult class of cases in which to obtain satisfactory results 
with amalgam are those opening alone upon the approximal surfaces of 
bicuspids and molars. While it is true that amalgam may be manip- 
ulated in spaces impossible with gold foil even in soft cylinders, it is 
essential that sufficient room be obtained for the perfect introduction of 
the material and its subsequent trimming and polishing ; for polishing 
is quite as necessary an operation with amalgam as with gold. This 
space is obtained either through wedging or by cutting through the 
occlusal face of the tooth into the cavity. 

Space is to be obtained and amalgam packed in such a manner 
that the amalgam at the completion of the operation shall exhibit no 



324 PLASTIC FILLING MATERIALS. 

evidence of pastiness. To insure the removal of the excess of the sol- 
vent, gold foil may be burnished over it as already described until it 
requires some effort to cut the mass with a lancet blade. Amalgam 
when set is more difficult to cut and polish than gold ; the greater por- 
tion of the carving is therefore done at the same sitting as the filling, 
but should never be undertaken while the filling is soft. It should be 
in such a condition that it is necessary to carve, not smear, it into shape. 

A suitable cutting instrument of the form of Nos. 37 to 40 of Flagg's 
set (see Fig. 286) is passed first across the cervical border of the filling, 
removing any excess due to imperfect contact of the matrix with the 
cervical margin of the cavity ; next the lateral borders are carved, and 
then the masticating surface. The body of the filling is left full, so that 
after two days, when the filling receives its final dressing and polishing 
with cuttlefish disks, strips, pumice, etc., the filling will be reduced to 
correct contour. A polished amalgam filling will retain an untarnished 
surface when an unpolished one will discolor very objectionably. 

Many of the cases in which it was at one time the usual prac- 
tice to fill or restore almost entire tooth crowns with amalgam, 
Fig. 293. are trimmed down, shaped, and artificial 

t crowns applied. One class of cases is fre- 

j*^^^^ quently seen in which the indication is for 
IWl|jj|pl\ an enormous amalgam filling rather than an 
k^^^B| artificial crown ; this is, the loss of the dis- 
Wp^ilP^ tn\ na ^ °f the crown of a molar. As a 
rule the teeth are pulpless, or it is necessary 
Restoration of lower molar with to Revitalize the pulp. The appearance of 
amalgam. the crown after the removal of carious den- 

tin and cutting away frail enamel walls is seen in Fig. 293. 

A Herbst matrix is fitted, closely embracing all the margins of the 
cavity. The rubber dam is adjusted. It is of course understood that 
the root canals have been properly sterilized and filled. The posterior 
canal is drilled out for about J in. and screw-tapped. A thin solution 
of zinc phosphate is mixed and the tip of a screw to fit the tapped 
root has its point dipped into the cement, and then quickly screwed 
into place. The amalgam is packed in larger masses than usual, using 
bibulous paper to compress it about the screw and into such scant 
undercuts as may be secured in the anterior portion of the tooth. The 
filling is completed with amalgam wafers. 

Such a filling should be well set before the rubber dam is removed. 
The upper surface is carved into cusps and sulci to occlude properly 
with the antagonizing teeth. The matrix should remain for twenty- 
four hours, when it may be split and removed. If the matrix has been 
exactly adjusted there should be no trimming of the margins required, 



USE OF AMALGAM. 325 

no carving of contour, and no smoothing, the amalgam being ready for 
polishing strips. The occlusal surface is smoothed and polished with 
moosehide points and pumice, using a stiff brush to polish the sulci. 

Finishing". — The process of finishing hard amalgam fillings is simi- 
lar to that of finishing gold. For example : a compound cavity occu- 
pying the approximal and occlusal faces of a molar. A fine saw is 
placed in a frame as in Fig. 294, but set to draw-cut with its teeth 

Fig. 294. 




The Kaeber saw frame. 

pointing toward the frame. The blade is passed above the cervical 
margin of the filling, engaging any projecting amalgam, which is then 
sawn off. It is just as essential with an amalgam as with a gold filling 
that the cervical edge should be exactly flush. 

The lateral margins of the filling are next carved smooth ; strips of 
emery cloth are passed into the interdental space and the filling smoothed 
and rounded, completing this portion of the operation with emery strips 
of the finest grit. 

Linen tapes or metal polishing strips are next charged with pumice 
and passed over the surfaces until they are smooth and the margins are 
perfect. The occlusal portion is polished by means of rubber or moose- 
hide points and pumice. 

Should it be a plain approximal filling, not a " contour," the saw is 
used to cut away surplus amalgam, and the polishing accomplished by 
means of disks and powders. 

Fillings upon the buccal surfaces of teeth are smoothed by means 
of disks and polished with rubber cups or disks and pumice. 

Gutta-percha. 
Origin. — The gutta-percha of commerce is the coagulated juice of 
the Isonandra gutta, a tree of the order of Sapotacece. The juice is 
found in all trees of this order, but some specimens are of much higher 
value than others. That from Borneo is regarded by manufacturers as 
being inferior ; it is the variety from which the name is derived — Malay, 
gatah or gittah, gum, and pertja, a tree. The gutta Tuban from Singa- 
pore is regarded as a superior variety. 



326 PLASTIC FILLING MATERIALS. 

The mode of securing the juice is by tapping the cambium layer of 
the tree and catching the juice as it exudes. From this stage to its 
formation into sheets it undergoes several processes (see works on gutta- 
percha) ; it is possible that in some of these operations it may have its 
texture injured by overheating. 

" The purified gutta-percha probably consists of a hydrocarbon (pure 
gutta) having the formula C 10 H 16 ; albane, C 10 H 16 O ; fluavile, C 40 H 64 O 3 ; 
and a variable compound named guttane. Pure gutta possesses all the 
good qualities of gutta-percha in a much enhanced degree, becoming 
soft and plastic on heating and hard and tenacious on cooling without 
being in the least brittle. The resins appear to be simply accessory 
components which have a decidedly detrimental effect when they pre- 
ponderate. Water, wood, fibers, bark, sand, etc., occur as mechanical 
impurities of gutta-percha." (Obach.) 

History. — Gutta-percha was introduced into dental practice as a fill- 
ing material about the year 1847. Soon after this a.secret preparation 
was introduced by a Dr. Hill, which received his name. Numerous 
alleged analyses of Hill's stopping have been given, all of which are 
untrustworthy. It was found to subserve so useful a purpose that it 
received the tribute of wide imitation ; in fact, the white gutta-percha 
preparations of the present day had their foundation in this imitation. 
There is no entirely trustworthy evidence that the original was superior 
to the best of contemporary preparations. 

As at present employed as a filling material gutta-percha is in two 
forms, the first the well-known pink gutta-percha base plate, which is 
colored by the insoluble sulfid of mercury, the second the white prep- 
arations, made firmer in texture by additions of the soluble zinc oxid. 
The specimens of crude gum differ as to the amount of heat required 
to soften them to an equal degree. Dr. Flagg l states that the speci- 
mens requiring the greatest degrees of heat for softening, prior to the 
addition of the zinc oxid, afford the best dental gutta-perchas. The 
method of making the gutta-percha of dentistry is by softening a mass 
of the brownish-yellow gum on a slab which has been heated over boil- 
ing water, and driving zinc oxid into the softened mass by a process 
of kneading, using a w r edge-shaped steel instrument as the kneader. It 
requires infinite patience and much time to distribute the powder evenly 
throughout the mass. Overheating the material at any stage of its 
manufacture or manipulation is ruinous to its texture. 

Classes. — Gutta-perchas are divided into three classes according to 
the temperature of softening : Loto heat, softening below 200° F. Me- 
dium heat, becomes plastic at 200° to 210° F. High heat, 210° to 218° F. 
The low-heat specimens contain 1 part by weight of gutta-percha to 4 

1 Plastics and Plastic Filling. 



GUTTA-PERCHA. 327 

of zinc oxid ; in medium-heat the ratio is 1 to 6 or 7 ; and in the high- 
heat specimens the gutta-percha is almost saturated with zinc oxid. 

Physical Properties. — Gutta-percha is an almost perfect non-con- 
ductor both of heat and electricity. It is less hard and rigid than any 
other filling material. It contracts in hardening, i. e. cooling. Softened 
masses of it are coherent when dry, but not when wet. Its color may 
be made to resemble that of the teeth. To vital tissues it is the most 
bland, unirritating filling material known. 

After it has served as a filling for a greater or less period it is found 
to have increased in hardness and difficulty of softening, and its surface, 
and perhaps its substance, has become porous in variable degree. The 
increased hardness is observed in such situations as those in which 
putrefactive decomposition occurs ; that is, in places where there is an 
evolution of hydrogen sulfid ; the gutta-percha apparently undergoes a 
species of vulcanization. It becomes somewhat porous in those situa- 
tions where the formation of a solvent is active (lactic acid), which 
abstracts the soluble zinc oxid from the mass. The pink variety con- 
taining the insoluble mercury sulfid does not become porous, but wears 
with a comparatively smooth surface when subjected to attrition. 

Examining in detail these several physical properties it will be noted 
that gutta-percha has but one property in common with gold — its insol- 
ubility. Its rational employment is therefore in such situations and 
conditions as those in which the use of gold is contraindicated. 

Indications for its Employment. — First, in its several forms it is 
employed as a temporary filling material for both the temporary and 
permanent teeth. Owing to its non-conductivity it is employed near 
the pulp ; its insolubility recommends its use at the cervical margins of 
cavities, particularly in the buccal cavities of molars which do not 
extend to the masticating surface, where the non-resistance of the 
material would cause its rapid wasting. 

This is the most common of the situations in which gutta-percha is 
applied : very deep cavities upon the buccal surfaces of molars, extend- 
ing beneath the gum, and having ragged enamel margins, the orifice 
of the cavity being much smaller than its body. Owing to its non- 
irritating quality, the condition of the gum in contact with a gutta- 
percha filling remains normal. 

It is used in approximal cavities of the anterior teeth which have a 
similar form to those just described ; also in labial cavities, particularly 
when these teeth are in any degree loose. For example : in a cavity 
opening alone upon the distal wall of a canine tooth the carious process 
has almost invaded the pulp, the enamel walls unsupported by dentin 
still retain their form and have a good texture. 

Pink base plate is invaluable for the temporary filling of spaces after 



328 



PLASTIC FILLING MATERIALS. 



wedging and also the cavities to be subsequently filled with metal. A 
mass of the material may be packed into such spaces and be permitted 
to remain for months if desired, the gum in contact with it after its 
prolonged presence exhibiting no indications of irritation. Masses of 
gutta-percha may be packed in interdental spaces where there is not 
sufficient space for the introduction of contour fillings, with the purpose 
of having the teeth gradually separated by the impact of mastication ; 
the gutta-percha acts as a persistent and very gradual wedge. 

When it has been determined that an excavated cavity is unfit for 
the reception of a permanent filling, gutta-percha is the filling material 
par excellence. 

Although it is stated that gutta-percha shrinks markedly in harden - 

Fig. 295. 




Flagg's gutta-percha softener and tool-heater. 



ing, cavities in which it has been properly placed exhibit no evidences 
of softening after the material has been worn for months, or it may be 



GUTTA-PERCHA. 



329 



for years. Particularly is this true when the pink variety has been 
employed and the method of introduction is correct. 

Mode of Softening-. — Gutta-percha should never 
be heated beyond a point which permits of accurate 
adaptation to undercuts and frail walls. The soften- 
ing should be gradual. Any heat in excess of this is 
not only harmful but ruinous. 

For its proper softening some device is necessary 
which shall permit of this type and degree of heating 
(see Figs. 295-297, 306). 

Fig. 295 illustrates the heater of Dr. Flagg. There 
are three metallic shelves, the highest of which receives 
the least amount of heat, and is designed for softening 
low-heat gutta-percha. The second shelf is for the 
softening of high-heat specimens. The lowest shelf 
and rack support the packing instruments, which are 
kept at a higher temperature than the filling material. 

Fig. 296 illustrates a device of Dr. L. A. Faught 
for the packing of gutta-percha. The heating wires 
connect at the bases of the instrument points, which 
are of aluminum, and sufficient heat is conveyed to the 
gutta-percha to maintain it in a plastic state during the 
packing operation. 

Instruments. — As a rule the instruments used in 
packing gutta-percha are too large and the material 
itself is used in too large pieces. If the cavity is of 
considerable extent, and usually it is, the filling should 
be introduced in four or more pieces. It is preferable 
to warm all the packing instruments so that the gutta- 
percha will remain plastic until perfectly adapted. 

Manipulation. — The rubber dam having been ad- 
justed, the cavity excavated and sterilized, the frail 
enamel edges broken away, without 
any particular object of margin form- 
ing, but to gain space, the cavity is 
dried for the reception of the gutta- 
percha. The field of operation should 
be dry, in order that each additional 
piece of gutta-percha shall adhere to 
its predecessor, which it avouIc! not do 
if wet. A softened pellet is taken upon the point of a 
probe and placed in the most inaccessible portion of 
the cavity and tapped into accurate contact with the tooth walls (by 




Order of placing 
gutta-percha pellets. 



Dr. Faught's electric 
heater. 



330 PLASTIC FILLING MATERIALS. 

means of the corkscrew plugger No. 32 or No. 33), as shown in 
No. 1 of Fig. 297. A second pellet is added (No. 2) and similarly 
manipulated. The Nos. 3, 4 pellets are packed in the order shown in 
the figure. In adding the last piece broad-faced instruments are used, 
adapting the gutta-percha accurately to the margins of the cavity. The 
softened gutta-percha may be made to adhere better to the walls of the 
cavity if these be first coated with one of the lining varnishes. 

Another method of manipulation is to line the walls of the cavity 
with pellets until a cylindrical cavity remains. A cylinder of gutta- 
percha of that size is nearly softened and pressed firmly into the cavity 
by means of a broad spatula. 

Should the cavity be very deep, the pulp almost exposed, the por- 
tion of dentin overlying the pulp is to be covered by a thin pellet of low- 
heat gutta-percha softened sufficiently to permit of adaptation. A disk 
of pink gutta-percha base plate answers admirably for this purpose. 

The use of one of the lining varnishes, noted at page 257, especially 
the cellulose solution known as kristaline, previous to placing the pellets, 
will insure their adhesion to the cavity walls and prevent rocking or 
tipping of the mass of gutta-percha during the operation of its insertion. 
In order to secure the best results the kristaline solution should be thin 
when applied, and the solvent completely evaporated by blasts of warm 
air before any attempt is made to introduce the gutta-percha, for unless 
the varnish lining is fully hardened the pellets will not strongly adhere 
to the surface so treated. 

Dr. How's Improved Gutta-percha Fillings. — Dr. W. Storer How 1 
has published a method of packing gutta-percha which is as excellent 
as rational, when the directions given are closely followed : 

" Many approximal cavities like C, Figs. 298, 299, may well be 

Fig. 298. Fig. 299. Fig. 300. 





Approximal cavities. 

filled with gutta-percha, and such as C, Fig. 299, where a gold filling 
would show through the thin enamel front, can better be filled with 
suitable gutta-percha. The section, Fig. 300, shows the angles A, A' , 
which should be given the enamel-edges when practicable, and in any 
case the enamel-margin should have a squarely defined angle at its 
surface border. 

" Cervico-labial or buccal cavities, as shown in Figs. 301-305, 
1 Dental Cosmos, 1892, vol. xxxiv. p. 281. 



G UTTA-PERCHA . 331 

admit of permanent gutta-percha fillings. Of course due attention 



Fig. 301. 



Fig. 302. 



Fig. 303. 



Fig. 304. 



Fig. 305. 





Cervico-labial and buccal cavities. 

must be given to the retention of the fillings by enlarging the interior 
walls of the cavities when they have not already such expansions. 
After suitably preparing the cavity, it should be made as dry as possible 
and so kept. The problem of conveniently and properly softening 
pellets of gutta-percha has been solved by the production of the ther- 
moscopic heater shown in Fig. 306, which approximates the exact size 

Fig. 306. 




Thermoscopic heater for gutta-percha. 

of the device. The heater is in this instance made of steatite, because 
of its heat-retaining property and the desirable physical qualities of its 
surface. The handle is of wood, at the opposite end from which, in 
the centre of the circular recess, is a small disk (A) of metal, fusible at 
about 212° F. On the heater near the metal a suitable number of 
gutta-percha pellets, as 1,1, are placed, and the heater held over the 
flame of the annealing lamp or burner (as in the illustration) until the 
fusible metal melts, when the heater is placed on a piece of cardboard 
(or an empty foil-book), and the gutta-percha will be found to be prop- 
erly softened. The steatite plaque retains the heat long enough for an 
ordinary operation, but if the metal meantime loses its fluidity and so 



332 PLASTIC FILLING MATERIALS. 

indicates a lowering of the standard heat, it may be quickly restored 
by a moment's holding of the heater over the flame, which will again 
fuse the metal. 

" When the flame is applied directly under the metal, as in the illus- 
tration, the material placed at 1 will, when the metal is seen to be fused, 
be at the heat of near 208° F., while the pellets at 2 will be heated to 
about 200°, those at 3 and 4 to near 194° and 180° respectively. Of 
course the location of the heat-source will produce corresponding varia- 
tions in the relative temperatures of the materials as severally situated ; 
but with a visibly definite standard such as the metal A, having a known 
fusing-point, the desired degree of heat may repeatedly be produced at 
any place on the receiving surface of the heater. A few seconds' contin- 
uance of the heater over the flame, after the metal has melted, will raise 
the surface heat to 212° or 215°, as the case may be ; but as a suitable 
indicator for a high-heat stopping, a button (B) of metal fusing at 230° 
is provided as a substitute for A, which is first melted and poured out 
on a piece of clean paper, the heater cavity being undercut so that 
when cold the metal cannot be shaken out. The boiling of a few 
drops of water in the heater cavity will likewise serve to indicate 
the proper temperature, but the fusible metal is in every way pref- 
erable. The best plan is to hold the heater over the flame until the 
-p o 07 metal melts, set down the heater, blow hot air 

into the previously prepared and dry cavity until 
the tooth is sensibly warm, hold the heater again 
over the flame to melt the metal, and then with a 
suitable broad and cold instrument pick from the 
heater a pellet or group of pellets sufficient to a little 
more than fill the cavity, and by a quick, firm, rock- 
Trimming margins of ing pressure force the mass into the cavity as if it 

gutta-percha filling. were sought ^ ^^ ^ impresgion of the game# 

Then dip the instrument into ice-water, wipe dry, and hold it firmly 
against the filling for one or more minutes, after which with a keen- 
edged thin blade pare off the surplus, cutting from the centre obliquely 
toward the margin, as in Fig. 307, taking great care that the filling B 
shall be flush with the cavity margin at every point, as at A, A', Figs. 
308 and 309. 

" Access to approximal cavities, as C, C, Figs. 298 and 299, will 
seldom permit the instantaneous mass-method just described, but in 
many such cases a warm, broad, flat blade, as stiff as the space will 
admit, can by repeated quick pressures be made to squeeze the soft mass 
into the cavity of the warmed tooth, and be instantly followed by a very 
thin strip of metal held tightly in both hands and wrapped with hard 
pressure over the filling around that side of the tooth, to both condense 




G UTTA-PERCHA. 



333 



and contour the plastic and produce the closest adaptation of the 
material to all parts of the cavity walls. 

" There is good reason for the belief that the common mode of suc- 
cessively introducing small pieces of imperfectly softened gutta-percha 
into a comparatively cold cavity, and employing instrument points more 
or less heated for packing the cooled plastic against one side of the 
cavity after the other, must in the nature of the case result in a leaky 
filling, such as gutta-percha is commonly said to make, whereas the 
defect is due not to the material, but to its inconsiderate manipulator. 

" In order to definitely determine whether or not suitably softened 
gutta-percha inserted by the mass-method will make a moisture-tight 
filling, some porcelain teeth of natural sizes and forms were made, hav- 



Fig. 308. 



Fig. 309. 



Fig. 310. 



Fig. 311. 



Fig. 312. Fig. 313. 



A'- 



A'-4 



ing cut in them, prior to baking, cavities of the class shown in Figs. 
298-305. These cavities have been filled with gutta-percha, leaving 
a surplus over the margins as at a, a', Fig. 310, and when quite cool 
paring them flush as at A, A', Figs. 308 and 309, and after several days' 
immersion in dilute aniline ink, the fillings have been removed without 
a trace of color showing on the walls of either the fillings or the cavi- 
ties. The only exceptions have been where the margins were rounded, 
as at a, a f , Fig. 310, and the fillings not cut below them as shown, but 
left feather-edged as at d, d' ', Fig. 312. In these few instances discolor- 
ations were found under the laps, but in no case extending farther than 
to A\ A', Fig. 313. The tests prove that under conditions as nearly 
practically parallel as extra-oral tests can well be, gutta-percha fillings 
properly made will exclude external moisture. Obviously, it is better 
to pare the filling below the enamel-slopes, as in Figs. 311 and 313, 
than to leave it overlapping, as in Figs. 310 and 312. For a final finish 
use a rapidly revolved, lightly touching cuttlefish-paper disk, followed 
by a wisp of bibulous paper or piece of tape wet with chloro-percha, 
applied for but an instant, to glaze the surface of the filling. 

" In the case of a very thin enamel front like that of Fig. 299, that 
part of the cavity O may be varnished with thin chloro-percha and dried 
with hot air just prior to filling it as before said. It might first be 
thinly coated with a tinted oxyphosphate or oxychlorid of zinc, which 




334 PLASTIC FILLING MATERIALS. 

should be given ample time to harden before placing the gutta-percha. 
Indeed, it is a fundamental feature of good gutta-percha 
work that while one cannot operate too rapidly when 
the plastic is at its proper temperature, the preparatory 
and completing processes should be given as much time, 
care, and close scrutiny as more elaborate and often less 
enduring gold operations. There is furthermore room 
for the exercise of the artistic faculty in having at hand chloro-percha, 
or cellulose varnish of varied colors, with which, by means of a small 
brush, a gutta-percha filling as B, Fig. 301, and one in the like cavity 
(7, may be given an inconspicuous shade, and the painting be renewed 
from time to time, if that be necessary by reason of wear. Fig. 314 is 
a sectional view of fillings like B, C, Fig. 301 ." 

Finishing' Gutta-percha Fillings. — If a gutta-percha filling has 
been packed with the proper amount of care and skill, it should require 
but little trimming. It should be undisturbed until cold. Its harden- 
ing may be hastened and intensified by holding ice-water in contact 
with it for a few moments. 

The portions overlying the margins are to be trimmed with extremely 
sharp lancets or by warm blades. Every cut should remove a little of 
the surplus material, never a mass of it, and should be made toward the 
cavity margins, never away from them. The filling should have been 
made so that no fulness is present to require reducing. 

It is a general practice to give a smooth face to a gutta-percha filling 
by wiping it with a tape slightly moistened, not wet, with chloroform. 
The surface produced by this means, although smooth, does not retain its 
' integrity so well as when the surface is formed by cutting. 

The use of gutta-percha as a canal filling is discussed in Chap. XVII. 

Basic Zinc Cements. 

Zinc Oxychlorid. — The basic zinc cements employed in dentistry are 
the oxychlorid and the phosphate ; the oxysulfate should also be included. 

The oxychlorid is formed by the combination of calcined and pul- 
verized zinc oxid with a solution of zinc chlorid : 

ZnO + ZnCl 2 + H 2 = 2ZnClHO. 

This compound was introduced as a dental filling material about 1850, 
its hardness, whiteness, and apparent insolubility recommending it for 
that purpose. It required no lengthy period of time to demonstrate 
that as a filling material per se it was unfit for use. It disintegrated 
rapidly and was not free from shrinkage. 

Properties. — Freshly mixed, this material is irritating to vital 
tissues with which it is brought in contact ; applied close to or upon an 
exposed pulp it may be productive of a transient or a persistent irritation, 



BASIC ZINC CEMENTS. 335 

or even inflammation. The extent of the irritation is largely governed 
by the fluidity of the cement paste, i. e. the amount of zinc chlorid present. 

It sets in fifteen minutes sufficiently to permit the packing upon it 
of an amalgam, and in half an hour a gold filling. After setting it is 
whiter though less hard than the zinc phosphate; it shrinks, particularly 
when used in large masses. It is a poor thermal conductor, and, like 
all bodies containing zinc oxid, is soluble in lactic acid — the usual sol- 
vent in the oral cavity. These several features are at present regarded 
as limiting the application of oxychlorid to — first, a lining material for 
carious cavities over which the insoluble filling proper is to be placed ; 
second, as a root-filling material (its use in this connection is discussed 
in Chapter XVII.). It is to be noted that the cement retains after 
setting an antiseptic power for a greater or less period. 

Use. — Zinc oxychlorid is usually employed as a lining material in 
teeth having what is known as poor structure — those in which caries 
proceeds to great depths without external evidence of the extent of 
invasion. After these cavities have been partially excavated it is found 
that further excavation and the removal of the deepest layers of the 
leathery dentin which appear to have retained sensitivity would prob- 
ably uncover the pulp ; it may be that the pulp has given subjective 
evidence of a mild attack of active hyperemia. 

In such cases the deepest layer of the partially disorganized dentin 
is permitted to remain and is subjected to the prolonged — fifteen minutes 
or longer — contact of hydrogen peroxid in the 25 per cent, ethereal 
solution (caustic pyrozone), 5 per cent, aqueous solution of formalin, 
or preferably a saturated solution of thymol in alcohol. The cavity 
walls are well dried with bibulous paper and the warm-air blast. 
Upon a mixing slab (see Fig. 315), a drop or two of the zinc chlorid 
is placed, and beside it a quantity of the zinc oxid powder. The 
powder is gradually incorporated with the fluid by means of a spatula 
until a creamy paste is made. A number of balls of bibulous paper 
are to be at hand. A portion of the paste is taken upon the end of 
an instrument and placed in the cavity, where it is quickly pressed into 
a layer against the cavity walls by means of the balls of bibulous paper. 
The walls are to be covered to a uniform depth of about one-sixteenth 
of an inch. The prompt application of the bibulous paper usually pre- 
vents any irritation due to the contact of the oxychlorid with the dentin 
overlying the pulp. Should the cavity be very deep it is advisable to 
protect the pulp by interposing a film of ethereal varnish between the 
oxychlorid and the dentin over the pulp. 

At the completion of the lining operation, the margins of the cavities 
are to be cleansed of the oxychlorid and the filling completed with the 
material indicated. 



336 PLASTIC FILLING MATERIALS. 

Zinc oxychlorid as an obtunding agent in the treatment of hyper- 
sensitive dentin is of considerable value, and its use for that purpose is 
described in Chapter VII. 

The use of zinc oxychlorid as a canal filling, and the mode of using 
it, are discussed in Chapter XVII. 

The powder of this cement is made of zinc oxid calcined and pow- 
dered, to which have been added substances (borax, silica, etc.) which 
affect its properties but little if at all. 

The fluid is made by dissolving pure zinc or its oxid in hydrochloric 
acid to the point of saturation ; or, by making a solution of zinc chlorid 
4 parts, water 3 parts, and filtering the solution. 

The use and effects of zinc oxychlorid as a pulp capping are dis- 
cussed in Chapter XVI. 

Zinc Phosphate. — These cements are nominally a combination of 
calcined zinc oxid with a syrupy solution of orthophosphoric acid : 

3ZnO + 2H 3 P0 4 = Zn 3 (P0 4 ) 2 + 3H 2 0, 

although their actual composition is more variable than that of any other 
filling material. Both base and solvent commonly contain impurities — 
those of the base owing to lack of discrimination, or worse, in the source 
of the oxid. Many of the impurities of the phosphoric acid are due 
primarily to the well-known inconstancy of the acid itself, and others to 
the mode of its manufacture. 

Many of the specimens of powder are prepared from commercial 
metallic zinc, and therefore contain the impurities of that metal. 
Among the latter is arsenic, so that the presence of arsenic compounds 
in inferior cement powders is by no means impossible, which may pos- 
sibly explain in some cases the death of non-exposed pulps in teeth 
which have been filled with zinc phosphate ; but as recent chemical in- 
vestigation has shown that the arsenic when present in cement powders 
is in the form of an insoluble zincarsenite, the danger of arsenical irrita- 
tion of the pulp from that source would seem to be a remote one. 

A common source of the glacial phosphoric (metaphosphoric) acid of 
commerce is from sodium phosphate, variable quantities of which are 
retained in the acid solution as acid sodium phosphate (dihydrogen 
sodium phosphate). This substance is soluble in water, and must there- 
fore greatly increase the solubility of any cement containing it. 

To properly make pure specimens of zinc oxid and phosphoric acid 
is a comparatively expensive operation — which will serve to explain the 
seemingly high cost of fine specimens of cement, and incidentally serve 
as a warning against the indiscriminate use of cheap cements. 

Making the Powder. — A quantity of pure zinc oxid is luted in a 



BASIC ZINC CEMENTS. 337 

sand crucible and kept at the highest forge-heat for hours. When cool 
the crucible is broken away and the vitreous inass of yellowish zinc oxid 
is reduced to a powder which will pass through a fine bolting cloth. 
This powder is placed in tightly stoppered bottles, for if exposed to the 
air it absorbs carbon dioxid and a portion of it is converted into the 
hydrated carbonate of zinc. This change may be noted in old powders 
by the effervescence due to the disengagement of carbonic oxid when 
phosphoric acid is added to them. Numerous substances have been 
added to the basal powder with the object of lessening the disintegra- 
tion, i. e. chemical solution, when used as a dental cement. Usually 
these additions are the oxids of other metals. The oxid of magnesium 
added to the powders causes the cement to set more rapidly ; the oxid of 
aluminum increases the rapidity of setting and makes a finer-grained 
cement, the central texture of which is, however, inferior. Cements of 
zinc oxid and phosphoric acid alone are apparently less soluble in lactic 
acid than when the oxids of aluminum and magnesium are added. 

Various other substances have been added which do not enter into 
chemical combination with the phosphoric acid, in the hope of confer- 
ring greater durability on the cement, but as yet but few of them have 
been shown to possess any value. 

The Fluid. — Phosphoric acid in its pure state is formed by hydrating 
phosphorus pentoxid : 

P 2 5 + 3H 2 = 2H 3 P0 4 . 

Much of the phosphoric acid used for cements is made by hydrating 
the glacial (metaphosphoric) acid, HPO s . The acid dissolves readily 
in water, being deliquescent when pure. Difficulty of solution is 
therefore an indication of impurity of the glacial acid. It requires a 
definite degree of heat to bring about the chemical hydration of the 
acid. At a temperature of 210° F. the union occurs, which is attended 
by the evolution of heat, the glacial acid being transformed into ortho- 
phosphoric acid. These acids are all hygroscopic. They will even ab- 
stract water from sulfuric acid. 

Impurities. — The commercial glacial acid is commonly, or as a rule, 
impure, containing variable amounts of sodium and magnesium phos- 
phates. These salts, particularly the dihydrogen (acid) sodium phos- 
phate, are permanently soluble in the phosphoric acid, and therefore 
give no evidence of their presence by the formation of precipitates. 
They are also soluble in water, which fact has a direct bearing upon the 
durability of cements made with the impure acid. 

It has been stated by writers that the acids of cement were occasion- 
ally the meta- and pyrophosphoric. A test of some of them said to be, 

22 



338 PLASTIC FILLING MATERIALS. 

of these varieties showed none of them to give the reaction of the pyro- 
acid ; a few giving traces of the meta- acid. 

Precipitates which form in cement fluids are probably metallic phos- 
phates. The instability of cement fluids is notorious. Aside from the 
known or probable contaminations which they may contain this insta- 
bility is to be regarded as a distinctive feature of phosphoric acid. 

The Cement. — To make the cement, successive portions of the oxid 
are mechanically incorporated with the fluid until a stiff paste results. 
In five minutes a ball made of the paste glazes, and rebounds when 
dropped upon a hard surface. It breaks with a granular surface ; in 
fifteen minutes it is cut with some difficulty. If the cement fluid con- 
tain the acid sodium phosphate, an acid reaction may remain for hours 
or days. The atmospheric conditions markedly modify the properties. 
In warm, or hot and moist weather, the setting is more rapid and it 
may be sudden. In cold weather it is delayed. The greater the dilu- 
tion (the thinner the fluid), the more rapid the setting. 

In its freshly mixed state zinc phosphate is adhesive, losing this 
property in a great degree when set, if surrounded by moisture. It has 
a higher rate of heat conductivity than zinc oxychlorid. 

Uses. — Its legitimate field of usefulness is in situations and under 
conditions where its advantageous properties may be utilized and its 
disadvantages minimized. One of the principal facts to be borne in 
mind is the solubility of the cement in lactic acid, which is present 
almost always about the necks of the teeth, in approximal spaces, and 
along gingival margins. Its clinical use is therefore attended by the 
greatest measure of success when placed at a distance from such situa- 
tions — as, for example, in cavities opening upon the masticating sur- 
faces of teeth, where its great hardness is an element of advantage. 
Good specimens have been known to last for periods varying from 
three to eight years. Dr. Henry Weston has cited cases where an un- 
usually good zinc phosphate filling has lasted for ten years. 

As a filling material per se y zinc phosphate has but limited employ- 
ment except for the teeth of children, and as a temporary filling in the 
teeth of adults. Times and occasions will suggest themselves to every 
operator where gold, amalgam, and gutta-percha are contraindicated as 
filling materials ; in such cases zinc phosphate performs a useful ser- 
vice. Its great field of usefulness — where, indeed, there is no substi- 
tute for it — is in the filling of the greater portion of extensive cavities, 
which are then filled and sealed with gold or amalgam, by an inlay, or it 
may be by a partial crown. It is invaluable, and in most cases indispen- 
sable, as the retaining medium of fixed bridge work and of many forms 
of artificial crowns. 

Prior to placing the zinc phosphate filling in a cavity, it is a wise 



BASIC ZINC CEMENTS. 



339 



Fig. 316. 



Dropper. 



Fig. 317. 




Scoop. 



Fig. 31: 



precaution to line the latter with one of the quick-drying ethereal var- 
nishes, to protect the dentinal walls from contact with acid sodium 
phosphate which may be present in the cement. In some cases the 
placing of the cement in proximity to a non-exposed pulp is productive 
of marked suffering. Should the cavity 
be very deep it is the usual practice to 
place a softened disk of gutta-percha 
over the wall nearest the pulp. The 
rubber dam should always be adjusted 
before the insertion of a phosphate fill- 
ing, to insure dryness not only during 
the insertion, but during the period of 
hardening, at least fifteen minutes. 

Mixing of Cement. — This is an 
operation of equal, if not greater, im- 
portance than any other in the manipu- 
lation of zinc phosphate. Dr. Henry 
Weston has demonstrated how, almost 
entirely, the mixing of cement gov- 
erns its stability. Specimens of the 
same powder and fluid mixed after dif- 
ferent methods gave entirely different 
results, not only in the appearance but 
also in the hardness, texture, and solu- 
bility. The method of mixing set forth 
is that of the same experimenter. As- 
suming for illustration that an approx- 
imal cavity is to receive a contour filling, 
or a large occlusal cavity is to be filled, 
Fig. 315. 



Glass mixing tablet, with rubber feet. 

or an extensive cavity is to be three- 
fourths filled with cement : 

A drop, or, where a large mass of 
cement is required, two drops of fluid are placed upon a scrupulously 
clean glass (Fig. 315) by means of the dropper shown in Fig. 316, and 



Spatula. 



340 



PLASTIC FILLING MATERIALS. 



a mass of powder, in great apparent excess of that required, is heaped 
at a distance from it, taken from the bottle by the scoop (Fig. 317). A 
portion of the powder is drawn into the fluid by means of a stout spatula 
(Fig. 318), and stirred with a rotary movement until a thin paste is 
made ; another portion of powder is then added and is slowly and thor- 
oughly incorporated ; more powder is added until the mass is as thick as 
putty and difficult to smear with the heavy spatula ; the mass is scraped 
together, taken from the spatula, and rolled between the forefinger and 
thumb, which have been well scrubbed. The mass is now kneaded, 
then rolled into an oblong pellet. 

If for an occlusal cavity a piece about one-fourth the size of the cavity 
is set in the deepest portion and tapped into perfect apposition with the 
cavity walls by means of a burnisher. Other pellets are added, and the 
process is repeated until the cavity is exactly full, the burnisher form- 
ing the surface of the filling and outlining clearly every margin of the 
cavity. The filling should remain under rubber dam for at least fifteen 
minutes — longer when possible. A coating of ethereal varnish, a solu- 
tion of gutta-percha in chloroform, or melted paraffin as suggested by 
Dr. Bonwill, is applied to the surface and the grinding of the filling 
deferred for a day or two. Should the cavity be upon an approximal 
side of a tooth, a matrix is to be employed ; the most satisfactory and 
quickly adapted instrument for this purpose is one of the composition 
silver strips used for carrying polishing powders (Fig. 319). A strip 

Fig. 319. 




Polishing strip. 



as wide as the length of the tooth is to have one end rolled upon itself 
until it forms a cylinder more than one-sixteenth of an inch thick (Fig. 
320, .4). The strip is passed into the next interdental space and drawn 



Fig. 320. 




through until the cylinder (A) rests firmly upon the teeth; the free end 
is now passed through the space into which the cavity opens ; where it 



BASIC ZINC CEMENTS. 



341 



Fig. 321. 



rests upon the lingual surface of the tooth it is burnished into contact 
with the edges of the cavity, forming walls to the latter (320, B). The 
cement is introduced as in the preceding case, and when the cavity is 
full the free end of the strip is drawn upon, compressing and round- 
ing the filling. Should the cement be an adhesive specimen or mixed 
thinner than described, the surface of the flexible mat- 
rix is to be faintly oiled by means of olive oil. 

At the completion of the operation the cement should 
be exactly flush with the margins except at the labial 
aspect, and the surface of the cement should have such 
smoothness that polishing is not necessary. Cement 
fillings are polished dry with the finest of cuttlefish 
disks. 

The process of filling the body of any cavity is the 
same, except when the enamel walls are thin and frail. 
In the latter case, where space permits, it is preferable 
to line the walls with the oxychlorid of zinc, over which 
the phosphate is placed. Before inserting a veneer fill- 
ing of gold or amalgam, each cavity margin must be 
scraped free from cement. 

When orthodontia appliances such as rings or caps, 
or prosthetic appliances, crowns and bridges, are to be 
set it is preferable to use a cement prepared for that 
purpose, although it is the general practice to use the 
cement to which the operator is accustomed, mixing it 
thinner than for filling purposes. Wherever possible, 
it is advisable to operate under rubber dam, even while 
setting orthodontia appliances. 

The tooth is cleansed with chloroform — as, for ex- 
ample, when a ring or cap is set — to remove fatty mat- 
ters, and a layer of shellac varnish applied, which is 
then dried by the air blast (chip blower). Cement 
paste is formed, of such consistence that it will flow 
readily and yet not be watery ; the inside of the band 
or cap is filled with cement by means of an appropriate 
spatula (Fig. 321) ; a layer of cement is placed on the 
tooth where it is to be embraced by the band, which is 
then pressed into position and is to remain without 
disturbance until it is hard. The application of bands 
or ligatures should be deferred until the following day. 
As soon as the cement is hard the surplus is cut away 
and the dam removed. 






Pointed spatula. 



342 PLASTIC FILLING MATERIALS. 

Temporary Stopping. 

Preparations of this name are compounds of gutta-percha with 
various substances added to lessen the temperature of softening. 

As procured from the manufacturer they are of two varieties, the 
adhesive and the non-adhesive — or, to be more precise, the less adhesive. 
The former preparations, the adhesive, are usually made of gutta-percha 
(generally the pink base plate), Burgundy pitch, white wax, and chalk 
or zinc oxid. In the non-adhesive varieties the Burgundy pitch is omitted. 
The latter varieties are usually made of a pink color, to furnish a safe- 
guard against mistaking a filling of temporary stopping for one of gutta- 
percha. 

As the name implies, they are designed for temporary use, retaining 
dressings in teeth, to maintain space between teeth which have been 
wedged apart, until the attendant pericementitis subsides ; to press away 
gum tissue overhanging the margins of a cavity ; to fill excavated cav- 
ities for a few days. 

Unlike gutta-percha, most of these preparations cannot be permitted 
to remain for a prolonged period ; they usually become offensive, par- 
ticularly so when the hygiene of the mouth does not receive proper 
attention. To maintain space and press away gum tissue they are used 
as gutta-percha ; their lower heat of softening permits their application 
close to the pulp of a tooth without the painful response associated with 
placing hot gutta-percha in the same position. A prominent use of the 
material is the sealing of arsenical applications in teeth. 

As with any other material, it is necessary, in order to have the 
minimum of pain, to make the 'application and manipulate the stopping 
so that no pressure shall be exerted upon the pulp. Temporary stop- 
ping is inferior to zinc phosphate for this purpose, as the latter may be 
flowed into a cavity and over an arsenical application without causing 
the slightest pressure. 

Should the cavity of decay extend to or beyond the gum, a small 
conical piece of the temporary stopping should be softened and packed 
carefully against the cervical margin and gum, to act as a guard to the 
latter against contact with the virulent irritant arsenic trioxid. The 
arsenical paste on a minute pledget of cotton is laid upon the exposed 
pulp — if the latter be hypersensitive, beside it — and the remainder of 
the cavity and interdental space are filled with one very soft piece of 
temporary stopping. 

Temporary stopping, in cones, has been used as a canal filling (see 
Chapter XVII.) and as a filling for the bulbous portion of pulp 
chambers. 

Another important use of the material is the sealing of the occlusal 
cavities of teeth which are under treatment for septic pericementitis. 



OXYSULFATE OF ZINC. 343 

Plugs of softened temporary stopping have been used for the arrest 
of alveolar hemorrhage ; also for the temporary setting of artificial 
crowns. 

Lining Varnishes. 

These are solutions of various gums and resins in alcohol, chloro- 
form, and ether, which are employed to furnish a non-conducting and 
impermeable film to cover the dentinal walls of excavated cavities. 

The first, sandarac varnish, is a thin solution of sandarac in alcohol. 

The second, a solution of virgin rubber in chloroform. 

The third a solution of hard Canada balsam, copal, or damar in 
ether. 

Another is the preparation known as kristaline, a solution of trinitro- 
cellulose in anhydrous amyl acetate. 

Before lining a cavity with zinc oxychlorid, a film of one of these 
varnishes, the quick-drying ones preferred, is applied, and when this is 
dry the cement may be inserted without causing pain. Varnishes have 
been used to furnish an adhesive surface upon which to pack gutta- 
percha fillings. It is always advisable to varnish the walls of a cavity 
which is to receive a filling of zinc phosphate, to prevent the action of 
any free acid or acid salt upon the dentinal walls. 

Some of these varnishes are admirable non-conductors, and serve 
in that capacity under gold or amalgam fillings in a most satisfactory 
manner. 

They may be used to prevent the tooth discoloration due to the pres- 
ence of amalgam, particularly of copper amalgam. 

OXYSULFATE OP ZlNC. 

What is known as the oxy sulfate of zinc in dental parlance is 
merely a thin zinc oxychlorid containing zinc sulfate. A true zinc 
oxysulfate is made by mixing a saturated solution of zinc sulfate with 
uncalcined zinc oxid. It forms a white paste which sets quickly and 
attains about the hardness of an inferior plaster-of-Paris. 

It is bland and unirritating to exposed pulps ; is a non-conductor ; 
is faintly and persistently astringent. 1 

Its principal use is as a pulp capping or protective. A thin paste is 
made, in which a disk of paper is dipped, then quickly and accurately 
laid upon the area of exposure. When hard (in a few seconds) a drop 
of fresh thin paste is flow T ed over the capping. The cavity may then be 
lined with zinc phosphate. 

As a pulp protector from thermal shock it is applied in a thin layer, 
and over it a lining of zinc phosphate is packed. 

1 J. Foster Flagg. 



CHAPTER XIV. 
COMBINATION 1 FILLINGS. 
By Dwight M. Clapp, D. M. D. 



The use of more than one material for filling a single cavity was 
suggested by the observation of the condition of fillings composed of 
but one material and noting the effects of time and use thereon. 

If a large number of amalgam fillings in crown cavities are exam- 
ined, many will be found to have imperfect edges. One cause of this 
imperfection is, undoubtedly, the brittle character of amalgam, in con- 
sequence of which the edges have become broken. In other words, 
amalgam as a filling material lacks edge strength. Its dark, sometimes 
almost black, color also renders it very objectionable, especially if used 
in conspicuous positions. 

If the same number of gold fillings in occlusal cavities are examined, 
the edges will be found in better condition than was the case with the 
amalgam. One reason for this is, undoubtedly, because gold is not 
brittle, but possesses sufficient edge strength to withstand the force 
of mastication. Its color is also less unsightly than that of amalgam. 
For occlusal cavities, therefore, gold is regarded as the better filling 
material. 

If a series of occluso-approximal cavities filled with gold be studied, 
it will be found that the teeth are in much better condition on the oc- 
clusal surface than at the cervical borders of the fillings. Compare gold 
fillings with a series of amalgam fillings in the same class of cavities, 
and the condition of the teeth will be reversed : at least a much larger 
percentage of the teeth will be found in good condition around the ap- 
proximal portion of the fillings than was the case with the gold. Hence, 
the deduction is inevitable that, of these two materials, amalgam is the 
better to fill the cervical portion of approximal cavities. 

1 The term "combination " is adopted for the various fillings here described, in which 
more than one material is used, because it seems to be the most comprehensive. The 
putting together of different materials in filling teeth makes in no sense a chemical combi- 
nation, in which "any part of the compound is the same as any other part of it." 
Strictly speaking, the fillings are more ' ' mixtures ' ' than " combinations.' ' According to 
the best authorities, however, the meaning given to combination makes its use here quite 
admissible. 

345 



346 COMBINATION FILLINGS. 

Zinc phosphate cement has many admirable qualities and is one of 
the most valuable filling materials known. It is easily worked, its color 
is good, its adhesiveness serves to bind tooth and filling together as the 
stonemason's cement unites the blocks of granite that he piles one on 
the other into one solid piece of masonry. As a tooth-saver it has no 
equal ; but its one great defect, its solubility in the fluids of the mouth,, 
restricts, in a great degree, its usefulness when exposed to these fluids. 

From this it will be easily understood why it is often desirable to 
combine in one filling two or more different materials ; and it may be 
said with truth that the operator who selects his filling materials with 
the best judgment, and combines and uses them with the most skill,, 
will save the greatest number of teeth. There would be just as much 
common sense and scientific reason for an electrician to make a dynamo 
entirely of copper, or a watchmaker to use nothing but gold in making 
a watch, as for a dentist to fill many of the cavities that come to him 
with but one material. 

It is an error to think that combination fillings are resorted to 
because more easily made than fillings of but one material, or that it 
indicates a lack of skill on the part of the operator who makes and 
recommends them. On the contrary, it is often much more difficult to 
make a suitable combination filling than one of any single material ; and 
the student will find that combination work will give ample opportunity 
for the employment of all the skill and ingenuity he may possess. 

Every operation must be made with the greatest amount of care and 
attention to minute details, or the object sought will be unattained, and 
the result be an inferior piece of work which will sooner or later cause 
grief to the patient and chagrin to the operator. 

It is impossible to describe all the combination fillings that have 
been found advantageous and useful, therefore only some of the most 
important will be considered in detail. The list is limited only by the 
perverse manner in which teeth decay, and by the ingenuity of the ope- 
rator to devise scientific and practical combinations to meet the cases 
presenting. 

It is to be understood in every instance in this chapter that the teeth 
are in proper condition to be filled without further treatment. If pulp- 
less, the roots are supposed to have been put in a healthy condition and 
filled. In cases of exposed, or nearly exposed, pulps, they are supposed 
to have been properly protected, and the teeth ready in every respect 
for the mechanical operation of inserting the fillings. 

Cement (Zinc Phosphate) and Amalgam. 

In Simple Cavities. — This combination is of the greatest service in 
saving badly decayed teeth that otherwise might have to be cut off and 



CEMENT AND AMALGAM. 



347 



Fig. 322. 




crowned, or perhaps lost altogether. The simplest cases where it may 
judiciously be employed are occlusal cavities. Many such cases are 
seen where there is little left but the enamel, which, however, is thick 
around the orifice of the cavity, and, if properly supported, will have 
sufficient strength to withstand the ordinary strain of mastication. 
Great care should be taken to remove the decay from every part of the 
cavity, being sure that none is left under the cusps or any part of the 
overhanging enamel. 

The edges of the cavity must be carefully trimmed, so that the filling 
can be finished flush with the external surface, in order not to leave any 
overhanging portion of amalgam to be broken off, as it certainly will be 
if so left, to the great injury of the filling. 

There are but few cases, even in occlusal cavities, where the rubber 
dam should not be used, at least for the final excava- 
tion and for putting in the filling ; for it is almost im- 
possible to be sure that all decay has been removed 
from a cavity unless it is dry. No filling should be 
allowed to get wet before it is all in place if it can 
possibly be avoided. It is much better to err by 
using the rubber dam too often than not often enough. 
Fig. 322 shows a cavity such as described. 

The cavity being ready, sufficient amalgam to fill 
one-third of it is prepared. Before introducing the amalgam, however, 
the cavity is filled two-thirds or three-fourths with rather soft cement, 
into which pieces of the prepared amalgam are crowded, forcing the 
cement into every portion of the cavity. The cement 
which has oozed out around the edges is then removed 
with an excavator, and the operation will have the ap- 
pearance shown in Fig. 323. The filling is then com- 
pleted in the same manner as an ordinary filling of 
amalgam in an occlusal cavity. 

The advantages of this kind of filling are many : The 
bulk of it is of cement, which does not change its shape 
perceptibly and is the best of materials when not ex- 
posed to the fluids of the mouth. The cement firmly 
unites the tooth to the filling, thus making a support to 
the frail walls as well as a stopping to the cavity. The 
amount of metal is reduced to just enough for a cover- 
ing of sufficient strength to guard the cement, and the tooth will not be 
discolored by the amalgam, as is often the case in teeth of not very 
dense structure, and especially in the mouths of young patients, when 
not thus protected. 

The combination of cement and amalgam, as described above for 



Large occlusal 
cavity. 



Fig. 323. 




Section showing 
amalgam and. 
cement. (Sur- 
plus cement 
must now be 
removed; then 
finish with 
amalgam.) 



348 COMBINATION FILLINGS. 

occlusal cavities, may be used in the same manner in simple approximal 
cavities in the molars and bicuspids, and even in the six front teeth, 
when the cavities are so situated that the amalgam does not show. 
When used in the front teeth the cement should be allowed to remain 
very near to the edges of the cavity. The amalgam need not be 
more in amount at this point than the thickness of an ordinary 

Fig. 324. 




Cement and amalgam filling in an incisor. The surplus cement has heen removed and the fill- 
ing is now ready for the finishing portions of amalgam : a, enamel ; b, cement ; c, amalgam. 

visiting card (see Fig. 324). For the front teeth very light colored 
amalgam should be selected, as color is of more importance than 
strength. 

In the temporary molars this combination can be used, frequently, 
with the greatest satisfaction, especially in those shallow approximal 
cavities where but little undercut can be obtained without exposing the 
pulp. The cement should be used quite thin, and the amalgam worked 
into it with a burnisher, or rounded instrument, forcing the cement to 
a feather edge at the margins of the cavity. In cases of this kind resto- 
ration of contour should not be attempted, as the force of mastication 
might serve to fracture the cement and dislodge the filling. In this 
manner many troublesome and difficult cavities can be successfully 
treated, and teeth made to last their allotted time that would otherwise 
be prematurely lost. 

In Compound Cavities. — A more extended description will be 
necessary for the treatment of compound cavities in the bicuspids and 
molars, especially where it is desirable to restore contour. In these 
cases a matrix is often a necessity. There are many matrices that may 
be used successfully, but, as they are described in other parts of this 
work, only one need be mentioned here. This is selected on account of 
being almost universal in its application. It can be made from any 
metal not acted on by the mercury contained in amalgam. German 
silver is inexpensive and seems to meet every requirement, and is, 
therefore, recommended. For ordinary use it should be from No. 35 to 
No. 38 gauge. If stiff it should be annealed, so as to be readily bent to 
the form of the tooth. It can be easily polished so as to reflect light 



CEMENT AND AMALGAM. 



349 



into the cavity, by drawing a narrow strip of it between two pieces of 
stationer's rubber (ink erasers). Place one piece of the rubber on a 
table, then the strip of metal held with pliers in one hand is placed on 
the cake of rubber, while with the other hand another piece of rubber 
is held firmly down on the metal, which is drawn between the two until 
sufficiently bright. 

For ordinary cases, a piece is cut from the German silver, as shown 
in Fig. 325, A, wide enough to extend from the top of the tooth to a 
little beyond the cervical wall of the cavity, and long enough to a little 
more than cover the cavity laterally when tied in place. Sometimes it 
is necessary to make the matrix with a lip to extend under the gum, as 
shown in Fig. 325, B, or in some other irregular form, so that it can be 



Fig. 325. 





A, Matrix and ligature; B, lipped matrix. 

made to properly fit the cavity. Special cases may require a very wide 
or a very narrow one. The operator's ingenuity must devise the right 
shape. 

For tying the matrix to the tooth, coarse, well-waxed floss silk is the 
best. It is passed through the holes punched in the metal, as shown 
in Fig. 325, A and B. When these holes are made, the edges must be 
finished smooth, or the silk will be cut when drawn tightly around the 

tooth. The operator must use tact as to 
Fig. 326. how and where to make his knots in 

tying on the matrix. Usually, a good 
way is to place one end of the ligature, a, 
between the teeth, then to make a sur- 
geon's knot, as shown in Fig. 326. The 
other end of the ligature, b, is then forced 
between the teeth, and the knot tightened. 
This will bring the knot between the 
teeth and opposite the matrix and will hold the latter until it can be 
shaped and bent into place with a burnisher or other suitable instru- 
ment. The knot is again tightened, and the two ends of the ligature 
carried to the back of the matrix and a similar knot tied there. The 
second knot, when drawn tightly against the back of the matrix, forces 
it closely up to the cervical border of the cavity, and makes a firm 
resistance when the filling is being condensed. The silk is then wound 




Manner of ligating the matrix. 



350 COMBINATION FILLINGS. 

round and round the tooth and matrix until it nearly covers both, or at 
least sufficiently to insure its remaining in place during the operation. 
A knot may be tied each time the silk is wound around the tooth, or 
not, as appears to be necessary. Sometimes, when the sides of the 
tooth are sloping, the ligature has a tendency to slip off. This can 
usually be overcome by turning back, with tweezers, the two upper 
corners, as shown in Fig. 331. To saturate the ligature with sandarac 
or other sticky varnish will sometimes be sufficient to prevent the same 
tendency. 

Fig. 327 illustrates a simple and delicate, but very powerful, little 
-p IG 3 27 slip matrix which is of great efficiency 

^ ^ . — ^ — ^ in the treatment of occluso-approximal 

^p^ ^gg- jgg"a_, cav ities. They were conceived originally 

%-J 1|L™J (CU iETI f° r * ne plastics, in which case they are 

left in place over night (the plastics thus 
setting under pressure), slipping out easily the next day away from the 
then hardened and perfectly contoured surface of the filling. 

" They are most easily made, even for each case (though in practice 
this is not necessary, as they may be employed over and over again), 
as follows: Suitable-shaped pieces, of a size to a little more than over- 
lap the cavity margins, are cut from thin . . . steel, ... all corners 
:and burred edges smoothly finished ; a tiny hole is punched close to 
the middle of both the buccal and lingual edges, and it is then laid 
upon a piece of lead and swaged (not merely bent, be it remarked) into 
perfect concavity, greater or less as the individual case shall require, 
by tapping with a hammer a convex rod of hardened steel laid upon it ; 
my own instrument being a round-headed picture nail, case-hardened, 
polished, and with twisted wire attached at right angles to a handle. 
Any amount or shape of concavity required for each case can thus be 
produced in a moment, either newly from blanks kept ready or changes 
made in those used for other cases to fit the one in hand, about a 
dozen of different sizes and degrees of convexity being sufficient to 
select from, with little or no changes for all ordinary cases. The 
tapping having re-stiffened the steel somewhat, taken in connection 
with the impingement of the convex face against the approximal 
surface of the adjoining tooth, gives firmness and strength to these 
delicate little strips and a perfect hugging fit to the surfaces of the 
tooth being filled, especially at its cervical margin, that is most 
satisfactory/' l 

When the cavity involves a large portion of the crown, or the mesial 
-and distal surfaces, the matrix should be long enough to almost encircle 

1 Dental Cosmos, June 1898, vol. xl. No. 6, p. 452. 




CEMENT AND AMALGAM. 351 

the tooth, the ends nearly joining against the sound remaining wall (see 
Fig. 328). In such cases it may be desirable to slit it one or more 
times, in order that it may be made to take the form of 
the tooth more easily (Fig. 329). 

After the tying is completed, a suitably shaped bur- 
nisher is used to form the matrix, by pressing it outward, 
to a proper contour. 

One of the desirable features of the matrix here de- 
scribed is the ease with which it is made to give just the 
right shape and contour to the filling. When used for 
gold fillings it yields enough so that with a little care in 
packing the gold can be forced beyond the margin of the cavity suf- 
ficiently to insure a flush filling when burnished, after removing the 
matrix. 

A matrix put on as described will have sufficient resistance for a gold 
filling; for amalgam, cement, or gutta-percha it 
may not be necessary to tie it quite so securely. 

For compound fillings of cement and amalgam 



two methods, A and B, are here given. 

7 . -I • -i -ii Matrix with marginal slits. 

A. Those cavities which, although large and 
involving much of the tooth, may have but small or comparatively small 
openings, especially if a matrix be used — and there are but few cases 
where the matrix is not advisable. If, after putting on the matrix, in 
this class of cavities, cement is introduced, and pieces of amalgam 
thrust into it, the cement will most likely be carried to the margin of 
the cavity at the cervical wall, and it Avill be found, after removing the 
matrix and finishing the filling, that a part of the external portion is 
of cement, and not being protected by the amalgam, would be washed out. 
To avoid this, a portion of the filling is made before the 
matrix is pat on. Cement is put in, followed immediately 
by the amalgam as described for " occlusal cavities " 
with the added complication of the missing approximal 
wall. After sufficient amalgam has been put into the 
cement the portion of the latter which may have oozed 
out must be carefully cut away, so as to expose the entire 
outer edge of the cavity, including the cervical ' tvall (see Cement lining and 

fe J 7 & V amalgam. 

Fig. 330). 

After this has been done, the matrix may be tied on and the filling 
completed as though it were but a simple cavity. Sometimes it is well 
to leave the matrix in place until the amalgam is fully set. If this be 
done, care must be taken that no sharp edge or corner of it be left to 
wound the tongue or cheek. 




352 



COMBINATION FILLINGS. 



Fig. 331. 




a, Matrix ; b, amalgam packed 
against the matrix ; c, por- 
tion of cavity to be nearly 
filled with cement and fin-, 
ished with amalgam. 



B. Cavities with large openings. The rubber dam and matrix 
having been adjusted, enough amalgam is packed 
against the matrix to form a shell of sufficient 
strength to make the approximal wall of the 
filling (see Fig. 331). 

This will leave a large portion of the cavity 
unfilled as shown in the figure ; in this space is 
placed cement, which is gently worked into the 
soft amalgam, but with care not to carry it 
through to the matrix. Before the cement be- 
comes hard more amalgam is put in, the sur- 
plus cement is removed, and the whole finished 
to look like an entire amalgam filling, while in reality it is only a shell 
of amalgam, perfectly fitting the outside of the cavity, cemented into 
place. If the walls of the tooth are frail, the cement will serve to 
greatly strengthen them. If, as some claim, large metal fillings alter 
sufficiently under changes of temperature to fracture frail walls, the 
danger is by this method reduced to a minimum, as the amount of metal 
is only just sufficient to give requisite strength. 

There is another class of cavities which may be described in this 
connection, presenting great difficulties in themselves, 
yet, with this simple matrix, they are often easily 
filled. It is those cases where decay has reached the 
alveolar border approximally, and extended on either 
the buccal or lingual portion of the tooth, or both, in 
such a manner that the dam cannot be made to stay 
beyond the cervical border of the cavity. If a liga- 
ture is used, it will draw into the lateral grooves of 
decay and be of no use (Fig. 332). 

The mode of treatment is as already described, 
with the exception that the matrix is adjusted before the rubber is put on. 
After the matrix is in place, it is but the work of a moment to put a 
Palmer clamp on to the tooth, and slip the rubber 
dam over clamp, matrix, and tooth. If the matrix 
has been carefully fitted there will be no trouble in 
keeping the cavity dry long enough for any ordinary 
operation. 

There are certain buccal cavities, also, below 

which it is difficult to retain the rubber dam. A 

very narrow matrix, adjusted with ligature and 

Matrix and clamp clam P ( Fi g- 333), over which the rubber is placed, 

adjusted, ready for w iH often greatly simplify the operation. Modifica- 

dam> tions of this method may also be applied to the 



Fig. 332. 




a, Alveolar line be- 
yond which the liga- 
ture cannot be made- 
to stay. 



Fig. 333. 




CEMENT AND GOLD. 353 

bicuspids, and sometimes even to marginal cavities in the incisors and 
canines, with good results. 



Cement and Gold. 

This combination may be used, with but slight modification, in the 
same manner and in the same class of cases that have been mentioned 
for the use of amalgam and cement, cases under B excepted. The 
cement is placed in the cavity, and, while soft, pieces of some of the 
so-called " plastic " golds are put into it, in the same manner as has 
been described for cement and amalgam ; the surplus cement is carefully 
cut away, and, after waiting for that in the cavity to become 
so hard as not to break or crumble under pressure, the pieces of gold 
placed in the soft cement are thoroughly condensed. For this pur- 
pose, de Trey's " Solila " Gold, Steurer's Plastic Gold, White's Crystal 
Mat Gold, and Watts' Crystal Gold are recommended. The filling 
can then be completed with the same or any kind of cohesive gold. 
Care must be taken to place a sufficient amount of the plastic 
gold into the cement to make, when condensed, a solid foundation 
upon which to build the rest of the filling. If too little gold has 
been used, it will " chop up " and not make a secure union with the 
cement. 

In some large cavities it may be found more convenient, after having 
filled the approximal portion with the cement and gold, to make a second 
mix of cement for the rest of the cavity, into which the gold is put as 
before. 

In some special cases it may be well to use foil in this manner, but, 
as a rule, the plastic golds will be found preferable. 

Too much stress cannot be laid on the desirability of this method 
for frail teeth, remembering always that the cement is the strengthening 
and supporting medium. The mason would not build a bridge pier of 
granite alone, or a house of bricks without mortar. However nicely 
the blocks of granite or the bricks might fit each other, it is the cement 
and the mortar that hold them together as in one piece. 

Especial attention is called to this combination of gold and cement 
for the six front teeth. In the teeth of young patients and teeth 
of low-grade structure there are often found large cavities which, 
if filled with gold alone, will in a few years, sometimes months, show 
discoloration around the fillings. Filled as above described, every 
vestige of decay having first been removed, a combination results which 
is the ideal preservative filling as far as present knowledge and facilities 
go. Pulpless front teeth that are much decayed can be improved in 
appearance and greatly strengthened by this method. Fig. 334 shows 

23 




354 COMBINATION FILLINGS. 

a cavity in a central incisor that can be filled to advantage with cement 
and gold. Fig. 335 shows a cavity in a central 
Fig. 334. Fig. 335. incisor with the pulp removed and but little of 
the -crown remaining but the enamel. The greater 
part of the cavity has been filled with cement into 
which plastic gold has been put and condensed. 
The filling can be completed with any cohesive 
gold. 

In compound cavities in molars and bicuspids, 
a, Frail enamel walls; after the cement and gold have been put in, as 
6, gold surface made by described for cement and amalgam J., and the 

plastic gold condensed , . t , i r , r -i i -t , i 

into cement. matrix adjusted, sojtjoiL can be used to great ad- 

vantage at the cervical portion of the cavities, as 
elsewhere described for using soft and cohesive golds. 

Amalgam and Gold. 

Gold may be used in combination with amalgam — A, by allowing 
the amalgam to become hard before adding the gold ; B, by adding 
the gold while the amalgam is soft and finishing the filling at one sitting. 

A. Allowing" the amalgam to harden and then adding* gold at a 
subsequent sitting will usually be done in compound cavities in bicus- 
pids and molars, for the purpose, principally, of overcoming the dark 
appearance of the amalgam. For instance, a filling involving the occlu- 
sal and mesial surfaces of an upper first molar will, in many mouths, 
show more or less, and, if of amalgam, be dark and unsightly. To 
avoid this, the cavity may be nearly filled with amalgam, leaving a 
portion of the occlusal surface and along the buccal wall (this being the 
part of the filling most likely to show) for completion with gold later. 

The matrix should be used as described for cement and amalgam 
fillings. It is a good plan to leave it in place, when convenient, until 
the amalgam is hard. Before adding the gold, it should be ascertained 
what part of the filling will show, and the amalgam trimmed and shaped 
so that the gold may form that portion of the filling that will be in 
sight. Fig. 336 shows a compound cavity in a molar partially filled with 
amalgam. The amalgam has been left until hard and the filling is now 
ready to be finished with gold. The figure also shows the cement 
lining under the amalgam. 

Suitable retaining places must be made in the amalgam to hold the 
gold in position, as there is no union between the two in this case, as 
there is when gold is added to unset amalgam. The gold being added 
makes a filling much superior in appearance to one entirely of amalgam. 
The gold will also make a better wearing material for the masticating 
surface, having better edge strength than the amalgam, and therefore 



AMALGAM AND GOLD. 



355 



being less liable to be broken away from the walls of the cavity by the 
force of mastication, as spoken of elsewhere. 

Large amalgam fillings, when it is not necessary to have gold added 
on account of color, will be greatly improved if a channel is made with 
a small fissure bur between the amalgam and the enamel, and this care- 
fully filled with gold (Fig. 337). 



Fig. 336. 



Fig. 337. 



Fig. 338. 






Occluso-approximal cavity 
partly filled with amal- 
gam ready for completion 
with gold: a, a, amal- 
gam ; b, cement lining. 



Amalgam and cement com- 
bination with channel cut 
in occlusal margin for re- 
ception of gold : a, amal- 
gam; b, gold; c, channel 
burred out ready for gold, 
shows also cement lining. 



Gold and amalgam com- 
bination in incisor: a, 
amalgam ; b, gold. 



All amalgam fillings when gold is intended to be added, should be 
put in with soft cement, whenever possible, as described for " Cement 
and Amalgam " fillings. This will prevent much of the discoloration 
from the amalgam, as well as strengthen the teeth. Many front teeth 
can be saved and made to look well by filling with cement and amal- 
gam, as before described, and, after the amalgam becomes hard, cutting 
away that portion which is in sight, and filling with gold (Fig. 338). 

B. Amalgam and gold fillings, the gold being added while the 
amalgam is soft. These fillings will be indicated, usually, in com- 
pound cavities of the molars, and in the occluso-distal and sometimes 
even the mesial surfaces of the bicuspids. The amalgam will occupy 
not more than one-quarter or one-third of the approximal portion of 
the cavity, but sometimes in distal cavities of molars it may be good 
judgment to have as much as three-fourths of that* portion of the fill- 
ing, amalgam. 

No operation requires greater attention to detail, or more neatness 
of execution, than w 7 here gold is used in conjunction with soft amalgam. 
If chips of the unset amalgam are left around the matrix, or in the folds 
of the rubber, or in any place where they may be caught up on the disk 
or finishing strip and rubbed over the surface of the gold while the 
filling is being finished, they will give it a coating of mercury and injure 
the appearance of the work. On the other hand, if the method given is 
followed carefully, no detail left out of account, no slovenly manipula- 
tion allowed to pass for neatness and tact in handling the materials, the. 



356 COMBINATION FILLINGS. 

fillings can be finished as soon as the last piece of gold is consolidated, 
without the least danger of mercury coating. 

In preparing the cavity for a filling of this kind, almost no tooth 
substance has to be cut away simply to get access to the cavity, to prop- 
erly start and pack the filling, as is often necessary if an entire gold 
filling is to be made. As a consequence, much valuable tooth substance 
is saved, for, so long as the decay is removed and frail edge walls are 
cut away, the amalgam can be perfectly packed, no matter how irregular 
the surface to which it is to be adapted. Of course, the excavation 
must be planned so that a filling of proper contour can be made, and 
walls cut back when by so doing future decay can be better guarded 
against. There will be many cases encountered, however, where, by 
this method, much of a tooth structure can be left, whereas if gold 
were to be used it would be necessary to cut, often causing severe 
pain, in order that the part might be properly filled. 

For the purpose of describing a simple combination filling of this 
kind, a cavity involving the occlusal and distal surface of an upper sec- 
ond bicuspid is selected as an example. In the first place, sufficient 
space must be secured for a filling of the right contour, and to allow 
for passing in a very thin strip for finishing the filling. It is best to 
secure this room by previous wedging. Space having been secured, the 
cavity is prepared with proper undercuts, and the walls of the approxi- 
mal part, to be filled with gold, made at as nearly a right angle to the 
matrix as possible. This is in order to facilitate packing the gold, it 
being very difficult to obtain a satisfactory margin if the walls form a 
very acute angle with the matrix. 

A matrix so adjusted that it will stand the pressure of putting in 
the filling without moving is an absolute necessity for this combination. 
It having been put on as described under the head of " Cement and 
Amalgam " fillings (page 349), enough amalgam is carefully packed at 
the cervical wall to fill one-fourth or one-third of that portion of the 
cavity. It should be thoroughly consolidated by using properly shaped 
instruments and sufficient force to drive it into every part of the cav- 
ity. It is a good plan to use small pellets of bibulous paper, forcing 
them against the amalgam with medium-sized instruments. The free 
mercury which rises to the surface should be carefully removed. It is 
well to put in considerably more amalgam than is to be left, cutting 
out the surplus, which method leaves a good surface upon which to 
begin with the gold. Before the gold is added, however, care should 
be taken to remove every chip of soft amalgam from the folds of the 
dam, or any that may be clinging to the matrix, or in any position 
where it might be brought in contact with the gold when finishing the 
filling. These chips will remain for a long time soft enough to coat 



AMALGAM AND GOLD. 



357 




the gold with mercury if rubbed against it, Fig. 339. 

therefore they must be disposed of or an 
unsatisfactory filling will be the result. 

The proper amount of amalgam having 
been packed in the cavity, medium-sized 
pieces of some of the plastic golds before 
referred to are immediately added. The 
instruments used first on the gold should be as large as the 
cavity will accommodate, as they will break it up less and 
more readily carry the piece where it is wanted, after which 
each piece of gold should be thoroughly condensed with 
smaller instruments. 

As soon as the gold touches the amalgam it will absorb 
mercury, and sometimes several pieces of the gold will be 
entirely amalgamated. The surface of the filling will be- 
come very granular, and " chop up " to a certain degree as 
the first pieces of gold are used, and the instrument will 
cause a peculiar squeaky sound as it is pressed against the 
filling. The condensation must be very thorough at this 
point of the work, or the filling will be porous and the union 
between the amalgam and gold unsatisfactory. If the work 
is thoroughly done, however, the filling will be just as strong 
at this point as any other. As piece after piece of the plastic 
gold is added, the mercury will soon cease to penetrate it, 
and the surface become entirely gold. As soon as this stage 
is reached, and no more mercury is visible, any kind of cohe- 
sive gold can be used for the remaining portion of the filling. 
Fig. 339 presents some instruments that have been found 
especially useful in this work. The gold may be packed 
with hand or mallet pressure, or both. 

After the gold is all packed the matrix is removed, and 
the filling finished with sandpaper disks, strips, burs, and 
stones, in the ordinary manner. For finishing the amalgam 
portion of the filling only fine disks or strips should be used. 
The amalgam being yet in a granular condition, and not 
thoroughly hard, will be dragged from the edges somewhat 
and made slightly imperfect if a coarse grade of sand or 
emery paper be used. 

The gold will not break away from a filling made in 
this manner, even if there be no undercut in the tooth for 
holding it ; the union with the amalgam will be quite suf- 
ficient to retain it. The cavity must have the proper shape, 



Gold-pack- 
ing instru- 
ments. 




358 COMBINATION FILLINGS. 

however, for holding in the filling as a whole, the same as if it were 
entirely of gold or amalgam. 

Cases may occur where it does not matter whether the amalgam 

and gold are firmly united or not ; then, instead of putting the plastic 

gold into the amalgam, soft foil may be used against it in the manner 

described for the combination of Ci soft" and "cohesive" golds (page 361). 

Having become familiar with the simplest form of fillings of amalgam 

and gold, it will be well now to go a step farther, and take up some of 

the complications that constantly occur. Even the small amount of 

amalgam that is used will sometimes discolor a tooth slightly, especially 

if the buccal wall is thin or if the tooth is not of very dense structure. 

When there is danger of this discoloration taking place, it can be largely 

prevented by placing a medium-sized pellet or fold of 

Fig. 340. foil, known as " gilded platinum," against the buccal 

wall of the cavity before putting in the amalgam. This 

foil being faced with platinum, which has but very slight 

affinity for mercury, the amalgam can be consolidated 

against it with little danger of discoloration following. 

On the mesial surface of bicuspids and molars it will 

a, Amalgam; b, not be enough, always, to put the gold and platinum foil 

gold extend- gignmst the buccal wall ; more or less of the proximo- 

mg on the ° ; # x 

buccal side buccal surface of the filling being exposed to view — i. e. 
nearly to the t bidden by the tooth anterior to it— it would look badly 

gum margin. J J 

if made of amalgam ; consequently, in these cases the 
gold must be carried to the cervical wall, as shown in Fig. 340, the 
amalgam occupying a triangular space. 



Cement, Amalgam, and Gold. 

There are many teeth with very large cavities and frail walls, that 
can be rendered serviceable for years and made to look surprisingly 
well by the use of this triple combination. For instance, a molar or 
bicuspid having lost its pulp and a large portion of its crown, and 
occupying a conspicuous position, presents to the conscientious dentist a 
serious problem. He knows that if filled with amalgam it will be an 
eyesore to every one by its unsightliness. If filled with gold it would 
take hours, and exhaust both patient and operator, and there would be 
every probability of the walls soon breaking away and the filling com- 
ing out, testifying to the poor judgment of the operator in recommend- 
ing such a filling under such circumstances. If filled with cement it 
will have to be refilled often, and with each refilling would more than 
likely be somewhat weakened. The loss of contour by the wasting away 
of the cement will allow the tooth to change position, and its usefulness 



GUTTA-PERCHA AND CEMENT. 



359 



will gradually be lost, and the tooth sacrificed because the dentist did 
not bring the requisite amount of knowledge and skill to his aid to 
meet the opportunity offered. It is in saving such teeth as these that 
the reputation of the dental profession for skill and usefulness is in- 
creased, and honor and gratitude are accorded to the men who can 
accomplish it. 

The method of procedure will vary according to the size, shape, and 
position of the cavity. If small, a little amalgam can be put into the 
soft cement before putting on the matrix, as described for " Cement and 
Amalgam " A, the surplus cement removed from the entire edge of the 
cavity, the matrix adjusted, more amalgam put in, and gold added, as 
described for "Amalgam and Gold." 

In larger cavities, involving more of the crown, after having filled 
the approximal portion of the cavity with the cement, amalgam, and 
gold, cement should be put in a second time, into which plastic gold is 
carried, and the filling completed by building gold on to that which was 
added to the amalgam, and joining it to that which was put into the 
second mix of cement. 

In still larger cavities, the matrix can be put on first, amalgam 

packed against it to form the outer 

shell of the approximal side, as 

described for " Cement and 

Amalgam" B; cement is then 

put into the body of the tooth, 

and into this gold is pressed (not 

amalgam) and afterward added 

to until it joins the amalgam, 

thus completing the metallic 

shell. From the specimen 

shown in Fig. 341 the matrix has been removed 

to better show the partially completed filling. 
It will be seen that the cement plays a very important part in this 
operation. It will preserve the color of the tooth though it may have 
been necessary to use a little of the gilded platinum, or to have the 
gold extend to the cervical border of the buccal corner of the cavity 
to support and bind firmly together the tooth and filling, yet it is pro- 
tected from external influences which would destroy it. Fig. 342 shows 
section of a filling of cement, amalgam, and gold. 



Fig 




Fig. 342. 



a, Amalgam and gold to 
form approximal shell 
of filling; b, cement 
and gold to which is 
to be added gold to 
complete the filling. 




Cement ; b, amal- 
gam ; c, gold. 



Gutta-Percha and Cement. 
This combination is extensively used for what may be termed tem- 
porary work, in the teeth of young patients, in teeth of poor quality, 
and in badly decayed and frail teeth. 



360 COMBINATION FILLINGS. 

It is generally believed that zinc phosphate will not last as well at, 
or just under, the gum margin in approximal cavities as will gutta- 
percha ; although exceptions might be taken to such a general rule. It 
is the common custom to combine these materials, placing the gutta- 
percha at cervical margins, using the cement for the occlusal and con- 
tour portions of the filling. 

There is no doubt that fillings of these materials last much better 
when inserted with considerable pressure, thereby condensing well and 
making them solid. In accomplishing this, the matrix is of great 
assistance. It not only allows force to be used on the material while 
in a plastic state, but prevents its being crowded out of the cavity and 
up into the gum, and leaves the filling in such condition that but little 
shaping and finishing are necessary. 

Any suitable matrix — the one previously described in this chapter 
is recommended — having been adjusted, gutta-percha sufficient to fill 
the cavity a little below the gum margin is carefully packed into place 
with warm instruments. Sufficient heat must be used to make it 
thoroughly plastic, but great care must be taken not to burn or overheat 
the material. If the gutta-percha is overheated its physical properties 
and durability are very much impaired. 

All cavities where gutta-percha is used should be varnished with a 
thin coating of white resin or Canada balsam dissolved in chloroform. 
This will prevent the dragging away of the gutta-percha from the walls 
of the cavity in finishing, and will make the filling water-tight. 

Sufficient gutta-percha having been put in, the rest of the cavity is 
filled with cement. The matrix being in place and properly shaped, the 
operation is reduced, practically, to that of filling an occlusal cavity. 

It is of great importance that the cavities be kept dry, consequently 
the, rubber dam should be used wherever it is possible to do so. The 
cement should be kept dry for at least fifteen minutes after it is put in, 
and then covered with varnish or vaselin to prevent the disagreeable 
taste due to its acid reaction, also to keep the filling for a still longer 
time from the saliva after the dam is removed. 

Cement will wear better if smooth and well polished. A fine glossy 
surface can be obtained with an oiled burnisher when the cement is at 
just the right degree of hardness, i. e. when but slightly plastic. 

A convenient method of oiling burnishers and other instruments for 
plastic fillings is to place on the back of the third joint of the forefinger 
of the left hand a bit of vaselin, half the size of a drop of water, just 
before beginning to put in the filling. The instrument can be readily 
touched to this, and it quite does away with the necessity for an " oil 
pad." 

An excellent lubricant for instruments used to manipulate gutta- 



GUTTA-PERCHA AND GOLD—VARIOVS KINDS OF GOLD. 361 

percha or cement is cocoa butter. A small porcelain druggist's jar 
into which it has been melted is convenient to have on the operating 
table. Plastic fillings will rarely stick to instruments that have been 
rubbed on cocoa butter. If a shaving of it is placed on a completed 
cement filling it will instantly melt and flow over the entire surface, 
preventing the disagreeable taste when the dam is removed, and will 
keep it from contact with the saliva for some time. 

Gutta-percha and Gold. 

For many years it has been the habit of some good operators to fill 
the interior of large cavities with gutta-percha, covering it with gold. 
Although this may not be objectionable practice in some cases, it cer- 
tainly cannot be recommended for general use. The principal objection 
to it is the danger of frail walls being fractured by the subsequent 
expansion of the gutta-percha. So many instances have been noticed 
where fracture has followed this combination that the fact seems well 
demonstrated that this danger exists. Again, there is no need of com- 
bining these two materials when zinc phosphate, which is so much 
better than gutta-percha for this purpose, is available and does not pos- 
sess the dangerous quality of expansion attributed to gutta-percha. 

Gutta-percha and Amalgam. 

What has been said in regard to gutta-percha and gold will apply 
equally well to gutta-percha and amalgam. Rarely, if ever, can this 
combination be used to so good advantage as can zinc phosphate and 
amalgam. 

Various Kinds of Gold in Combination. 

(A) The So-called Plastic or Crystal Mat Gold, with Other 
Forms of Gold. — Within a few years, preparations of gold other 
than that known as foil, or foil made into cylinders, ropes, and so 
forth, have been introduced and have become of great value in the 
filling of teeth. 

These golds are commonly known as " plastic gold." The term is, 
however, misapplied. The granular quality of these gold preparations, 
i. e. lack of fiber, is what gives them their peculiar and, for certain 
purposes, very valuable working qualities. To understand this charac- 
teristic, take a piece of White's " crystal mat gold " and place it upon 
a piece of blotting paper, then press the point of a medium-sized gold 
packer upon the centre. It will be observed that when the pressure is 
applied the gold is not inclined to curl up, but rests in its flat posi- 
tion, and the instrument has cut a clean track in the gold, condensing 
only that which is directly under the point. The gold being without 



362 



COMBINATION FILLINGS. 



Fig. 344. 



" fiber/' so to speak, the particles not directly under the point are not 
drawn down as the pressure is applied. This is why this preparation 
of gold is so useful for starting fillings. 

Now take a cylinder made of gold foil, place it on blotting paper as 
before, and with the same instrument press on the centre of it. It will 
be noticed that the instrument does not make a clean cut through the 
cylinder, as was the case with the piece of mat gold, and, instead of 
remaining flat on the blotting paper, it is inclined to curl up. The 
fibrous quality of the foil is an advantage when a corner is to be built 
on to a tooth, or in any place where toughness of the material assists in 
its manipulation. 

By using these golds for starting cavities, the peculiar qualities just 
referred to will be exhibited. For illustration, we will take an extreme 
case — that of a shallow circular cavity in the buccal surface of a lower 
molar. This cavity is entirely without angles or undercuts, its walls 
flaring outward, the bottom being flat, 
or as nearly so as it can be made with 
a large bur (see Fig. 343). A piece of 
plastic gold a little larger than the 
cavity is placed in position, then with 

Fig. 343. 



a-i 



Royce plugging instruments. 

a flat, very slightly serrated instrument («, Fig. 339) it is carefully and 
gently worked into place. When it is condensed about even with the 
outer edge of the cavity, a smaller instrument is used to condense 
around the edge. As only the portion of gold under the point is dis- 
turbed, this can be done quite readily without dislodging the whole piece. 
Soon sufficient force can be used to thoroughly condense the whole. 
Care must be used in selecting a first piece that it be not too large, but 
large enough, so that it will not chop up as it is being manipulated. 
After getting the first piece in place, the filling can be finished with the 
same or any other preparation of gold. If of the same, it is well to 
use oval points (Fig. 344) and work the gold toward the sides of the 
cavity with a sort of rotary motion, keeping the edges of the filling 
higher than the centre. 

This gold is very soft and takes a very sharp impression of the sur- 





VARIOUS KINDS OF GOLD IN COMBINATION. 363 

face on which it is packed, as shown by the cross lines on the filling, a, 
Fig. 343, which are reproduced from those made in the cavity shown 
at b in Fig. 343. The lines across the bottom of the cavity were made 
with the sharp point of a hatchet excavator. 

This form of gold can be used to advantage, sometimes, at the cervi- 
cal wall of compound cavities, provided a matrix has been tightly ad- 
justed. For starting fillings in approximal cavities in the front teeth it 
is sometimes invaluable, and it can be used in conjunction with any other 
form of gold, or interchangeably. If at any point in a filling the oper- 
ator sees a place w T here he thinks he can put a piece of plastic gold 
better than any other, there is no reason why he should not use it. 
Sometimes it is particularly useful to thrust into soft foil to make a sur- 
face upon which to build cohesive foil.- It can be packed with either 
hand or mallet force, and with smooth or serrated instruments. 

(B) Non-cohesive and Cohesive Gold. — Strictly speaking, non- 
cohesive gold cannot be made cohesive by annealing, and can be used 
only on what is known as the " wedge " principle. " Soft gold," as the 
term is generally understood, is non-cohesive when used without anneal- 
ing, but when annealed it becomes cohesive. 

Softness and toughness are the qualities necessary to make tight joints 
between fillings and cavity walls, and good preparations of non-cohesive 
and soft golds have these qualities. Consequently, a method that will 
admit the use of these golds against cavity walls with a sufficient amount 
of cohesive gold added to insure strength and hardness, when strength 
and hardness are necessary, is desirable. 

An exaggerated illustration of stopping a cavity watertight with soft 
or cohesive gold is that of stopping a bottle tightly by using a velvet 
cork or a piece of hickory. It can be done with the hickory, but the 
time required to do it perfectly, as compared with doing it with the 
velvet cork, is not unlike the difference between making a filling of soft 
and one of cohesive gold. 

Simple cavities, whether in occlusal or approximal surfaces, can often 
t>e half or two-thirds filled with soft gold in a very few minutes, and 
the rest of the cavity filled with cohesive gold. A filling made in this 
manner is as good as, or even better than, one made entirely of cohesive 
foil, and the time required to do it is much less, as the soft gold can, on 
account of its softness, be used much faster than can the cohesive. In 
cavities of easy access the soft gold can be so manipulated as to be 
against the walls of the cavity at every point. Small cylinders, or any 
other form of soft gold, can be set around the edges, and the central 
portion of the cavity filled with cohesive gold. Care must be taken to 
carry the cohesive gold into the soft with instruments not too large, so 
that a mechanical union between the two golds is effected, as but little 



364 COMBINATION FILLINGS. 

cohesion can be had between soft and cohesive gold. In large cavities, 
after the first pieces of soft gold have been put in place and cohesive 
gold worked in, the two kinds of gold can be used interchangeably. A 
piece of soft gold can be placed against a portion of the Avail of the cav- 
ity, followed by a piece of cohesive, which is first attached to the cohe- 
sive portion of the filling and then used to force the piece of soft gold 
to its place. Dexterity and tact in using these two golds together can 
only be obtained by experience, and carefully noting the characteristics 
exhibited under manipulation. 

In compound cavities soft gold pla} T s a most important part. Fill- 
ings in these cavities fail, usually, at the cervical wall, and too much 
care cannot be taken in making them at this place as nearly perfect as 
possible. For this purpose it is now generally conceded that soft gold 
is much better than cohesive. 

A suitable matrix will greatly facilitate the operation and assist in 
obtaining the proper contour. The thorough packing of the gold will 
also be much simplified if the cavity is so prepared that the walls form 
no acute angles with the matrix, therefore attention to this point is 
important. 

A matrix having been properly adjusted — the one described under 
" Amalgam and Gold " fillings is recommended — one-half or two-thirds 
of the approximal portion of the cavity is filled with soft gold. For this 
purpose soft cylinders, ropes, pellets, or mats can be used. Great care 
must be taken in condensing the gold that it does not tilt under the 
instrument. The pressure should force the matrix away from the tooth 
enough to allow the gold to be condensed just a little over the edge of 
the cavity, so that when the burnisher is applied there will be sufficient 
gold to make a flush filling. 

When all the soft gold has been put in that the case will allow, the 
cohesive gold should first be added in very small pieces in order to 
facilitate the driving of it into the soft gold, so as to make a strong 
union between the two. For this purpose very small cohesive cylin- 
ders or No. 3 or No. 4 foil will generally be used, but sometimes No* 
30 or No. 60 foil or some of the plastic or crystal gold can be used. 
The filling can be finished with any cohesive gold, that kind being 
selected which the operator has found by experience he can best manipu- 
late under the existing conditions. He will also remember, as the 
work goes on, that a piece of soft gold laid against an exposed wall,, 
and backed up with cohesive, as before described, will do much toward 
securing a good filling. 

(C) Soft, or Cohesive Gold, and Heavy Gold. — Fillings of soft 
or cohesive gold, or a combination of the two, should sometimes be 
finished with heavy gold. Nos. 30, 40, 60, and sometimes No. 120, 



GOLD AND TIN— TIN-GOLD. 365 

can be used to advantage. These heavy golds — which are usually 
rolled, not beaten — make a very dense filling, and, when great strength 
and hardness are required, they are preferable to lighter grades. 

When a filling that is to be finished with heavy gold has been 
brought to the point where the thick gold is to be added, the surface 
should be as nearly level as possible, as it is difficult to adapt the heavy 
gold to indentations and irregularities. The instruments used should 
have the very finest serrations, if any at all. The gold can be put on 
by hand or mallet pressure, or by burnishing with oval points having 
very slight serrations, or with an ordinary burnisher. "When done in 
this way the burnisher is apt to become gold plated, and the instrument 
will stick to and drag away the gold. When this happens the gold 
plating can be removed from the steel by rubbing on a piece of ink 
eraser, or on flour-of-emery paper. 

In using heavy gold great care is necessary that no portion of the 
piece added be left, uncondensed. Hard pressure must be applied to 
every part of the gold, or it will flake off and destroy the good appear- 
ance, if not the utility, of the filling. 

Gold and Tin. 

Compound cavities are sometimes partially filled with tin and then 
finished with gold. 

At the present time it is a disputed question whether tin, if used as 
above suggested, will not be dissolved out, after a time, by the action 
upon it of the fluids of the mouth, leaving a cavity. 

It can be used exactly as described for soft and cohesive golds, sub- 
stituting the tin for the soft gold, or for a portion of it — for, as a rule, 
much less tin would be used than soft gold. 

If desired enough tin can be used to cover the cervical wall, followed 
by sufficient soft gold to complete one-half or two-thirds of the filling, 
the final finish being of cohesive gold. 

The matrix will be found of the same service as in the case of soft 
and cohesive gold. 

Tin-Gold. 

The term " tin-gold " has been applied to the combination of tin and 
gold when a sheet of tin and a sheet of gold have been laid one upon 
the other, and rolled, folded, or crimped together, being then used in 
the same manner as non-cohesive foil, depending on the " wedge " prin- 
ciple for holding in the filling. Various authorities recommend differ- 
ent proportions of the tin and gold to be used in this manner. All the 
way from one-quarter of tin to three-quarters of gold, i. e. the propor- 
tion of one-quarter of a sheet of tin and three-quarters of a sheet of 



366 



COMBINATION FILLINGS. 



gold to be folded or crimped together, to three-quarters of tin and one- 
quarter of gold. A convenient way of preparing "tin-gold" for use 

Fig. 345. 




Foil crimpers. 



Fig. 346. 




Crimped tin-gold. 



in medium-sized cavities is to take one-third of a sheet of No. 4 
tin foil, upon which one-third of a sheet of No. 4 non-cohesive foil 

is laid. It is then placed upon 
crimpers (Fig. 345) and drawn into 
an evenly folded mass (Fig. 346). 

This is to be cut into lengths 
suitable to be used for the cavity in 
hand. These pieces can be doubled 
to make blocks, or rolled around a broach into cylinders, if desired. 
For larger cavities one-half, two-thirds, or even a whole sheet each 
of the tin and gold foils can be used. For very small cavities, one- 
quarter sheet of each may be sufficient. 

If it be a fact, as often claimed, that tin has peculiar preservative 
qualities as a filling material, it will be best to so crimp or fold the 
" tin-gold " that the tin will be on the outside, in order that it may be 
placed against the cavity walls. 

To obtain good results with this combination, it must be used with 
the same care and accuracy that are required for working gold. It is 
very tough and soft, and can be worked with great rapidity by an 
expert. For method of using see chapter on Non-cohesive Gold, and 
work " tin-gold " as there described for non-cohesive gold. 

After a filling of " tin-gold " has been in for some time it will often 
be found to have changed in character, and instead of being a mass of 
malleable metal, as it was when put in, to have become hard and brittle, 
closely resembling amalgam, but, unlike it, will not stain or discolor 
the teeth. 

" Tin-gold " is recommended for use in the temporary teeth, in 
occlusal and buccal cavities of molars, especially in teeth of poor qual- 
ity, and in the mouths of young patients. Small approximal cavities 



AMALGAMS OF DIFFERENT QUALITY— CEMENT AND ALLOY. 367 

in all the teeth may be filled with it to good advantage, when located 
where its dark color will not be objectionable. 

"Tin-gold" and Gold. — "Tin-gold" can be used in connection 
with gold in the same manner as has been described for the use of tin 
and gold, or soft and cohesive golds. 

Amalgams of Different Quality in Combination. 

For certain amalgams is claimed a greater preservative character 
than is possessed by others. But on account of very dark color or 
little edge strength l they may be undesirable for the surface of fillings, 
especially when contour is necessary, or when prominently exposed to 
view. 

In simple cavities it is very easy to fill nearly full with the amalgam 
deemed best for its preservative qualities, and to finish with that having 
superior color or edge strength as the case may require. 

For compound cavities fill about two-thirds with the first-mentioned 
amalgam, cutting away the surfaces and exposing the entire outer rim 
of the cavity, as shown in Fig. 336. The matrix is then adjusted and 
the remaining portion of the cavity filled with amalgam having the 
requisite edge strength for contour work. 

Cement and Alloy. 

Mixing alloys (such as used for amalgam) with cement has been 
recommended to a certain extent. This can be done by adding from 
25 to 50 per cent, of the alloy filings to the cement powder and then 
mixing with the liquid, or the alloy may be worked into a thin mix of 
cement. 

The object of the alloy is to protect the cement, in a measure, from 
the fluids of the mouth, thereby making the filling more lasting. 

Another combination of cement and alloy which has proved of con- 
siderable worth, especially where it is impossible to secure proper re- 
tention for an ordinary amalgam filling, the combination having a very 
strong adhesive quality, is thus described by a well-known writer : 

" Ordinary alloy should be used, and not the recently introduced 
quick-setting varieties. On the mixing slab should be placed a quantity 
of zinc oxid powder and a sufficient quantity of the liquid. Now mix 
the alloy in the usual way, but do not express the mercury, unless in 
considerable excess, as a very dry mix is difficult to incorporate with 
the cement. Mix the cement as usual for use as a filling, and immedi- 
ately mix in about an equal quantity of amalgam, using a stiff steel 
spatula. The white metal or bronze spatula should not be used, as it is 
acted upon by the mercury. Now you have a stiff plastic mass, which. 
1 See Chapter XIII. ; also writings of Dr. J. Foster Flagg. 



368 COMBINATION FILLINGS. 

may be rolled between the thumb and finger into a convenient pellet 
and placed entire in the cavity, pressing carefully to place with smooth 
burnishers. A perfect contour may be built up without the aid of a 
matrix. 

" The mixture is extremely adhesive to the dry cavity walls, and no 
definite retaining shape is needed. Some of the amalgam may be saved 
unmixed with the cement, and can now be burnished over the surface 
of the combination filling, to which it adheres almost greedily, and thus 
a pure metallic surface, like a veneer, is given it which is as durable as 
an amalgam filling. Or a quick-setting amalgam may be employed 
for the veneering. 

" In color this combination is like amalgam, but is more granular in 
appearance, and in its working properties resembles stiff cement. When 
hard it takes on a metallic luster under the burnisher ; if sawed through 
it shows a metallic surface. It is less soluble in the oral fluids than 
oxyphosphate cement, but less durable than amalgam alone, except when 
veneered with amalgam as described. 

" Its advantages over amalgam are, first, its adhesiveness, which 
property makes it applicable to cavities in which, for any reason, a re- 
tentive form cannot be obtained ; secondly, the rapidity with which a 
large cavity can be filled, a valuable item where dryness cannot be long 
maintained, and making it unnecessary to employ the rubber dam in 
many cases ; thirdly, the ease with which large contours may be made 
without using a matrix. 

" Its advantages over cement are its greater hardness and durability, 
but it is less agreeable in color, hence should be employed only in the 
posterior teeth." 



CHAPTEE XV. 

RESTORATION OF TEETH BY CEMENTED INLAYS. 

By Joseph Head, D. D. S., M. D. 



Strictly speaking, the term inlay may be applied to any substance 
placed in a tooth cavity, but custom has restricted this term to fillings 
inserted as one piece. 

In primitive times teeth were filled by driving a solid piece of lead 
into the cavity ; gum mastic was also used in the same way ; and the 
green stone inlays in the central incisors of a human skull discovered 
at Copan, Honduras, probably antedate all historical record. 

Before describing the construction of inlays it may be well to con- 
sider their advantages and disadvantages ; for if they have no superi- 
ority over other fillings to counterbalance their inherent defects, inlays 
are without excuse for existence. 

Let us, therefore, first consider the main characteristics of the per- 
fect filling ; and then by a comparative table of other filling materials 
the good and bad points of each may be justly examined. 

The characteristics of an ideal filling may be stated as follows : 

1. Resistance to wear of mastication. 

2. Resistance to action of oral fluids. 

3. Harmony of color. 

4. Exclusion of bacteria, and preclusion from growth of those that 
enter the margin. 

5. Non-conductivity of heat. 

6. Manipulation easy to patient. 

7. Manipulation easy to operator. 

8. Manipulation not destructive of healthy tooth structure. 

By a study of the table on page 370 cohesive gold will be seen to pos- 
sess over all other materials the sole, though important, superiority of 
greatest edge strength and resistance to the crushing force of mastication. 
True, it excludes bacteria from the cavity ; but experience proves that 
if the edges of a cohesive gold filling begin to leak and admit micro- 
organisms, the gold seems to be almost entirely lacking in the antiseptic 
power possessed by tin, amalgam, gutta-percha, and the cements. And 

24 369 



370 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



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INLAYS COMPARED WITH OTHER FILLINGS. 371 

while it resists perfectly the action of the oral fluids, it so utterly lacks 
the other ideal attributes, as already enumerated, that with front teeth, 
soft teeth, and teeth of nervous patients its manifest disadvantages 
more than counterbalance its advantages. 

Soft gold is open to the same objections, but it has the advantages 
of resistance to wear, resistance to oral fluids, and, to a less degree, 
exclusion of bacteria. 

Tin has to a marked degree the good and bad attributes of soft gold, 
but it turns black. 

Amalgam bulges under mastication, chips on the edges, rusts, and 
leaks; it prevents decay, however, through antiseptic action. When 
rusty it is a moderately poor conductor of heat, it is easy of adap- 
tation both for operator and patient, and calls for a manner of manipu- 
lation that is conservative of healthy tooth structure. It is therefore 
often available where gold is not. 

Oxyphosphate of zinc has all the advantages lacking in cohesive gold 
with the exception of color, and lacks all the advantages that cohesive 
gold possesses. Its edge strength is solely due to its great adhesion. 
It wears under mastication, dissolves in the fluids of the mouth, and 
usually absorbs bacteria ; but, on the other hand, it prevents the growth 
of germs, is a non-conductor of heat, has better color than gold, is 
easy of insertion for patient and operator, preserves weak walls, and 
does not require undercuts. 

The same may be said of oxychlorid of zinc, except that it causes 
pain to sensitive dentin and exposed gums. 

Gutta-percha, in a similar way, with the exception of color, possesses 
the good points lacking in cohesive gold, and lacks the good points pos- 
sessed by cohesive gold. It loses shape and wears under mastication, 
has feeble resistance to fluids of the mouth, has poor color, and leaks 
micro-organisms ; but, on the other hand, it inhibits from further growth 
the germs that enter, is a non-conductor of heat, is easy of insertion for 
both patient and dentist, and has a manipulation that tends to conserve 
frail though healthy walls. 

When we come to inlays we have a filling in which the good points 
of the cement are combined with those of amalgam, gold, or porcelain 
in such a way as to insure the advantages of both in the largest degree, 
and to reduce to a minimum the disadvantages of each. 

When a cavity is lined with a thin zinc cement squeezed out by the 
insertion of soft amalgam, this amalgam afterward having as much as 
possible of its mercury removed and the edges of the metal burnished 
to the cavity margins, an inlay of amalgam is to all intents and purposes 
made. This treatment takes away from the amalgam three of its objec- 
tionable features, conductivity of heat, lack of adhesion to the cavity, 



372 RESTORATION OF TEETH BY CEMENTED INLAYS. 

and discoloration of adjacent tooth structure, while the adaptation of 
the plastic metal to the tooth margins can be quite as perfect as though 
no cement were used. So in using the principle of the inlay with 
amalgam three distinct advantages are gained without any counteracting 
disadvantages, all of which would seem to indicate that whenever possi- 
ble zinc cement should be used under amalgam. 

When an inlay of gold is cemented into a cavity with oxyphosphate 
of zinc all the advantages of cohesive gold and oxyphosphate of zinc are 
obtained, excepting that a fine line of cement remaining at the margins 
may in time prove a source of weakness. Except in the fine line above 
mentioned, such a filling compared with the ideal filling possesses ex- 
cellent resistance to mastication and to the action of oral fluids, it has 
power to restrain the growth of bacteria that may enter, it is a non- 
conductor of heat, and is easy for the patient, while the manipulation 
involves no greater labor or loss of tooth structure than is entailed in 
the use of cohesive gold. The two objections that can be raised against 
the filling are bad color and an edge protected by a soluble cement. 
Hence — given a firm tooth structure that can bear the mallet without 
danger of being crushed, a dentin not sensitive to thermal changes, 
and a patient not too severely prostrated by the necessary malleting — a 
cohesive gold filling is superior to a gold inlay, inasmuch as the cohe- 
sive filling may have edges that perfectly exclude bacteria, even though 
it has no antiseptic action. Though the inlay largely inhibits from 
growth the germs that enter its margins, it nevertheless does allow 
them to enter ; and the filling that keeps out the germs entirely must 
be held superior to the filling that admits germs and then inhibits or 
destroys them. Unfortunately, in the soft, sensitive teeth of nervous 
patients the manipulation of cohesive gold does not result in the exclusion 
of decay germs. The tooth margins are powdered or weakened in some 
way by the manipulation or apposition of the gold, and the entering 
germs cause rapid decay, the cohesive gold not having the antiseptic 
power of restraining them. The thermal shocks, and the overwrought 
condition of the patient that sometimes lasts longer than can be avoided, 
both tend to produce unhealthy conditions of the mouth and consequent 
tooth dissolution. In such a mouth the inlay is indicated, as the patient 
should not be made to undergo the malleting ; and since the germs of 
decay will probably enter under any circumstances, it is necessary to use 
a filling the action of which will inhibit or prevent their growth. 

In approximal cavities where the filling does not show, and where 
great resistance to the percussive force of mastication is necessary, the 
gold inlay is usually to be preferred. Its sole objection is .the 'fine line 
of cement that connects it with the cavity walls ; but if the gold inlay 
be properly prepared, burnished, and finished as hereafter described, 



PORCELAIN COMPARED WITH OTHER MATERIALS. 373 

this line of cement may be rendered so microscopic as to become prac- 
tically no longer a source of danger. In other respects the gold inlay, 
when not visible, approaches very nearly the requirements of the ideal 
filling, having the advantages of perfect resistance to mastication, pre- 
clusion from growth of bacteria, non-conductivity of variations in tem- 
perature, easy manipulation, firm adherence to cavity walls, and an 
adaptation not usually so expensive to tooth structure as is the ordinary 
insertion of a gold filling. 

We shall now speak of the porcelain inlay, which in labial and buccal 
cavities fulfills more nearly than any other the characteristics of the ideal 
filling. Such a filling may possess color that really matches the tooth. 
It may be set with a cellulose cement that almost absolutely resists the 
oral fluids. It excludes germs of decay and precludes from growth 
those that enter. A porcelain inlay is a non-conductor of heat, it 
adheres to cavity walls, its manipulation is easy to the patient, and is con- 
servative of tooth structure. The only real objection to labial porcelain 
fillings is in the fact that great skill and patience are required in their 
insertion. Where, however, porcelain inlays have to withstand heavy 
strain in mastication, as in Figs. 370, 375, and 376, they are liable to chip 
on the edges, and thus to demand the use of oxyphosphate of zinc as a 
cement. This objection, therefore, renders them somewhat less service- 
able than gold inlays for non-visible approximal cavities in molars and 
bicuspids. For while the porcelain is sufficiently strong to withstand 
the crushing force of mastication, the chipping of the margin tends to 
accentuate the weakness already found in the solubility of the cement, 
which is its sole defence against bacteria. If such chipping occurs on 
the masticating surface of the molars or bicuspids, the fractured mar- 
gins can be readily filled with gold in such a way that edge strength 
equal to gold is obtained. Also, if the edges of the inlays are painted 
with insoluble cellulose 1 before the filling is cemented into place, all the 
strength and adhesibility of oxyphosphate of zinc can be combined. 
Thus with care and patience the porcelain inlay acquires the advantages 
of gold, cement, and porcelain, while it has none of the usual disad- 
vantages. The porcelain filling properly guarded may have the natural 
color possessed by no other filling material, strength to withstand masti- 
cation, resistance to the fluids of the mouth, power to exclude bacteria 
and to inhibit the growth of those that enter, non-conductivity of heat, 
adaptation, and conservatism of tooth structure. And if at times the 
manipulation for the dentist is of necessity so deft and artistic that the 
highest skill and judgment are required, it is but further evidence that 
the finest work is usually the most difficult. 

x The Doyle cement, a cellulose cement, is claimed to be permanent, and seems 
promising, but only years of experience can prove its value. 



374 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



The Porcelain Inlay. — The work of manufacturing and manipu- 
lating porcelain inlays remains to be considered. 

Pieces of porcelain matching the natural tooth have, in times past, 
been ground to fit the cavities and then held in position with cement. 
This class of work, however, is hardly feasible except in labial cavities 
on the surfaces of the front teeth. An excellent method for obtaining 

Fig. 347. 







a b c d e 

a, Defect at gingival margin ; b, cavity prepared ; c, mark of edge on tin foil ; d, tin foil cut out 

and glued to artificial tooth ; e, piece of porcelain ground and cemented into the cavity. 

good adaptation is to proceed as follows : A piece of tin-foil should be 
lightly burnished over the prepared cavity, as in Fig. 347, b, and the 
edges thoroughly outlined either with a burnisher or a plug of cotton 
lightly pressed into the cavity, making the foil appear as in Fig. 347, c. 

Fig. 348. 

e@99 

0000 

lOOOOOOOOoo 
POOOODOOIC8I0 

Porcelain cavity stoppers. 

The foil within the line of demarkation is then cut out and glued to 
the surface of a piece of porcelain that matches the tooth, as in Fig. 
347, d, the porcelain is ground away up to the edges of the tin on all 
sides, and a moderately good fit is thus secured (Fig. 347, e). This 
method, however, is superseded by recent discoveries ; but for those 
who are interested historically Fig. 347, illustrating the steps of the 
operation, may prove of value. Ready-made porcelain inlays have been 
kept in stock for years at the dental depots. These stoppings are of 
different shapes and sizes, and are intended to be ground to fit the cav- 



THE PORCELAIN INLAY. 



375 



ities and finally to be cemented in place (Fig. 348). Some, however, 
instead of being ground to fit the cavity, require the cavity to be 
ground to fit them. Dr. George H. AVeagant has devised a set of 
instruments suitable for this purpose (Fig. 349), consisting of five tre- 
phines of consecutive sizes made of copper charged with diamond 
dust. These instruments are intended to cut pieces of porcelain out of 
an artificial tooth that matches the color of the natural tooth, and the 
cavity in the natural tooth is prepared with one of Dr. How's inlay 



Fig. 349. 



Fig. 350. 




© 




■ m 



Dr. Weagant's diamond trephines. 



Dr. How's inlay burs. 



Fig. 351. 




burs (Fig. 350) corresponding in size to the trephine. This method has 
several serious objections, one of the principal being that in order to 
give the cavity a circular shape much sound tooth structure is usually 
sacrificed. Take for example the decayed spot shown in Fig. 351, a. 
This would have to be enlarged as in Fig. 351, b, 
— a very serious objection. 

As early as 1882 Dr. Herbst advocated glass 
fillings. These were made by taking impressions 
of the cavity in wax and making two moulds in 
some such material as plaster or asbestos. The 
ground glass was then flowed into the first mould, 
in which most of the shrinkage occurred. The 

partly formed filling was then removed and placed in the second 
mould, when more glass was added until the filling was complete. 
Even with this crude method the results were fairly satisfactory, although 
the margins were far from perfect and the glass was permeable to such 
an extent as to blacken ; nevertheless, fillings were made that preserved 
the teeth for years. 

In 1887 Dr. C. H. Land made mechanically perfect edges possible 
by devising the metal matrix. He used both gold and platinum, but 
found the latter preferable, as platinum could be adapted with a facility 
equal to gold, and allowed the use of a high-fusing tooth body much 
stronger and less likely to deteriorate than bodies capable of being fused 



376 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



on gold, these of necessity requiring so large a percentage of glass that 
they, like the fillings of Herbst, lacked permanence of gloss and color. 
From this discovery of Land dates all effective porcelain filling. Before 
this, pieces of porcelain had been ground to fit labial cavities, with 
fairly good results, and pieces of enamel from extracted teeth had been 
inserted in a similar fashion, but the accurate adaptation of porcelain to 
approximal cavities as far back as the molars was impossible until the 
metal matrix was evolved. 

At present the advocates of porcelain fillings are represented by two 
distinct parties : those who advocate a low-fusing porcelain that can be 
melted in a gold matrix, and those who advocate a porcelain of a fusing- 
point and resistance at least equal to Close's continuous-gum body, 

Fig. 352. 







12 3 

Diamond points, Nos. 1 to 



4 5 6 

a, copper disk charged with diamond dust. 



necessitating the use of platinum for the matrix. It is claimed by the 
advocates of low-fusing porcelains that gold can be more perfectly 
adapted as a matrix than platinum. This, if true, is a very important 
advantage. But, on the other hand, those advocating high-fusing 
porcelains believe that they can get as perfect an adaptation with 
platinum as with gold, and that their porcelains have a better color, 
are stronger, more durable, and more easily manipulated, thus giving to 
the work a far wider range than seems possible with any low-fusing 
bodies yet devised, for porcelains seem to have strength and durability 
in direct proportion to their fusing-points. In this connection we should 
remember that when brilliant men of the past, through long series of 
experiments, were perfecting the process of continuous-gum work, they 
would undoubtedly have adopted the low-fusing bodies had they found 
any that would melt on gold and remain permanent. That they 
finally resorted to platinum and made durable porcelain bodies at their 
present fusing-points would seem to indicate that low-fusing porcelains 



THE PORCELAIN INLAY. 



377 



are unable to withstand the solvent action of saliva and the force of 
mastication. 

The preparation of the cavity for either high-fusing or low-fusing 
porcelains is identical. The cavities should be free from undercuts. If 

Fig. 353. Fig. 354. Fig. 355. Fig. 356. Fig. 357. Fig. 358. 




these are unavoidable through extensive decay, the cavity should first 
be filled with oxyphosphate of zinc. The edges should be sharp and 



378 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



smooth, and where they are approximal there must be sufficient separa- 
tion to allow the metallic matrix, or mould, to be withdrawn without 



Fig. 359. 




A, Outline of labial cavity ; B, platinum foil large enough to be readily held immovable by the 
first and second fingers during the formation of the matrix. 

distortion, as success is impossible with a distorted matrix. The final 
polishing can be best accomplished with a set of diamond points (Fig. 352). 

Fig. 360. 




A, Outline of cavity in distal aspect of lateral incisor : B, platinum folded over cutting edge to 
insure immobility and to give outlines of tooth so that a perfect contour of porcelain may be 
obtained. 

The separation may be obtained with rubber, cotton, or tape. Approx- 
imal cavities between front teeth may be sometimes advantageously cut 



THE PORCELAIN INLAY. 



379 



freely away from the back, as in Fig. 374, a, b, c, d. When the 
fillings are between bicuspids the palatal or lingual walls should be cut 
unsparingly whenever it is necessary. Where the filling is to stand the 
force of mastication the edges of the cavity should be at least at right 
angles to the grinding surface, as in Figs. 370 and 375. The prepara- 
tion of the cavity being completed, if high-fusing porcelain is to be 
used the matrix must be made with rolled platinum one one-thousandth 
of an inch in thickness. If found desirable, thinner platinum may be 
used for small cavities ; but the firm burnishing required usually re- 
duces the foil of one one-thousandth of an inch to one three-thousandth 

Fig. 361. 




A, Cavity in anterior approximal surface of first molar. 

or one four-thousandth of an inch on the margins, where excessive 
thickness of the metal is objectionable. Foil thinner than one one- 
thousandth of an inch seems to lack sufficient body to stretch properly 
without tearing. This platinum, if annealed in a Bunsen burner or 
blowpipe, will be harsh and unfit for use, but when annealed in a muffle 
or electric furnace it becomes soft and tough. The platinum is placed im- 
movably over the cavity and spun into all parts with a ball burnisher 
(Figs. 353 and 354), great care being taken to define the edges sharply 
and smoothly. The edges that wrinkle may be flattened and smoothed 
with the broad surfaces of the spatula shown in Fig. 356. Should the 
bottom tear, it is of little moment as long as the edges are smooth and 
intact. Sometimes it is useful to form the matrix by driving the metal 



380 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



into all the recesses with cotton ; but while this is undoubtedly of 
advantage in some instances, the careful spinning of a piece of foil 
from the edges to the cavity floor will generally give the best results. 
The soft, unburnished platinum takes a beautiful impression, but when 
the metal has been burnished it becomes elastic ; if therefore the matrix 
be moved during its formation, an accurate impression is impossible, 
for the elastic platinum when distorted cannot be forced back accurately 
into position until it has been reannealed. When complaint is made 



Fig. 362. 




J, Posterior 



ipproximal cavity in second bicuspid ; B, edge of platinum extending over first 
bicuspid to insure mobility. 



against platinum by the advocates of gold matrices it probably arises 
from the fact that they try to work the platinum in the same manner 
as gold. 

The matrix when finished should be carefully removed and heated 
to redness in order to destroy all organic material, as such material will 
tend to destroy the true shade of the porcelain. 

In labial cavities the piece of platinum should be cut sufficiently 
large to extend beyond the two adjacent teeth, and the metal should be 
moulded to the three teeth by pressure with cotton and bibulous paper. 
The metal is then held firmly upon the two adjacent teeth by the first 
and second fingers, as in Fig. 359, when the general directions for adjust- 
ing the matrix to the cavity may be readily carried out. The large 
piece of platinum has two great advantages : it conduces to immobility 



THE PORCELAIN INLAY. 



381 



of the metal during the formation of the matrix, and it gives the entire 
labial form of the tooth, so that an accurate idea may be obtained of 
the desired contour of the filling. 

In corners of centrals, as in Fig. 360, the platinum should be folded 
well over the labial and palatal surfaces of the tooth ; then it should 

Fig. 363. 




A, Outline of approximal cavity : B, flap of platinum that had been cut away and turned back to 
facilitate the removal of the matrix. 

also be bent over the cutting edge, forming a sort of cap, beneath which 
shows the entire contour of the tooth, and by means of which entire 

Fig. 364. 




A, Outline of cavity as formed in platinum matrix ; B, clamp holding platinum immovable while 
the matrix is being burnished into place. 

immobility may be obtained while the cavity margins are being defined 
and the matrix formed. 

The same principle applies in forming a half cap from a large piece 
of platinum for the approximal cavities of bicuspids and molars. The 
platinum should extend, as in Figs. 361 and 362, from grinding edge to 
cervical margin, and along the sides of the adjacent tooth. This can be 



382 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



firmly held with the index and middle fingers of the left hand, while 
the right hand presses the metal with cotton partly into the cavity. The 
margins and floor of the matrix may then be defined with a burnisher. 

In mesial cavities the metal must be pushed away from the operator 
and the work accomplished by means of the index and middle fingers, 
as in Fig. 361. In distal cavities the metal is pulled toward the oper- 
ator, who works around and beyond the hand, holding the platinum as 
in Fig. 362. 

When, as sometimes occurs, the adapted platinum is dovetailed 
around the teeth, so as to render its removal difficult or impossible with- 

Fig. 365. 




Position of fingers : left lower bicuspid. 



out distortion, the outer edge of the platinum cap may be split with a 
sharp knife from the gum line, just beyond the cavity margins, as is 
shown in Fig. 363. Fig. 364 shows a method of obtaining immobility 
of the matrix by a clamp that sometimes proves useful. Figs. 365 
and 366 show the position of the fingers when manipulating the 
matrix on the lower teeth. This, of course, should be done while the 
matrix is held motionless in the cavity. It is sometimes advisable, in 
order that perfect immobility may be obtained, first to pack the matrix 
full of bibulous paper or cotton. When this is done and the packing 



THE PORCELAIN INLAY. 



383 



removed there will be no difficulty in teasing out an undistorted matrix 
from the cavity. 

The color of the filling must next be decided by means of a shade 
ring. The basal color of nine-tenths of all porcelain fillings is light 
yellow, and white added according to necessity will in a large number 
of cases be all that is required to obtain a perfect match. Whatever tint 
is desired, the basal color should be first ascertained, when the correct 
toning material may be added with comparative ease. The thoroughly 
mixed body, being wet with distilled w r ater and dried with blotting-paper 
to the consistence of dough, is placed in the matrix on the point of the 
brush or spatula (Figs. 357 and 358), and settled to the bottom with a 
few taps on the pliers that hold the platinum. The porcelain should not 



Fig. 366. 




Position of fingers : right lower bicuspid. 

be allowed to come quite to the edge. After it has been carefully dried by 
turning it face downward on a piece of soft muslin, the filling is placed 
in an electric or gas furnace, as the case may be, and baked until a gloss 
appears. It is then removed, cooled, and placed again accurately in the 
cavity, and the edges once more burnished down. 

This second burnishing is the most important part of the operation, 
for however perfect the first adaptation may have been, the edges must 
of necessity be warped in the furnace by the unequal expansion and 
contraction of the porcelain and platinum. This contraction having for 
the most part occurred, a second burnishing makes an adaptation that 
may be practically perfect. The partially filled matrix must then be 
removed, filled up to the edges with porcelain paste, and finally baked. 



384 RESTORATION OF TEETH BY CEMENTED INLAYS. 

A third addition of porcelain may be needed, but this is usually unnec- 
essary. After baking, the filling may be taken from the furnace almost 
immediately, as practically only very large pieces need to be cooled 
slowly, although theoretically a gradual cooling will make the porcelain 
tougher. The platinum should now be stripped off, care being taken 
to pull it away from the edge. Should it be pulled off toward the edge, 
chipping is likely to occur. If small portions of platinum stick to the 
porcelain, they can be peeled off with a sharp, tempered, pointed 
instrument. 

The filling is now ready for insertion. Undercuts may be carefully 
made in the cavity and grooves made in the porcelain, by using a thin 
copper disk (Fig. 352, a) charged with diamond dust, so as not to mar 
the edges. This is usually, if the proper method is employed, a safe and 
easy procedure with the smallest fillings. The disk and porcelain must 
be kept thoroughly wet during the cutting of the grooves. The inlay 
should be so held that the edge adjacent to the intended groove may be 
buried in the skin of the finger ; the groove can then be fearlessly made 
by the swiftly revolving disk that cuts only the hard porcelain and 
pushes back the yielding tissue of the finger without inflicting injury. 
If the porcelain is blackened by the powdered copper, the discoloration 
may be readily removed by a strong jet of water thrown upon it. If, 
however, the undercuts are not deemed feasible or sufficient, the gloss 
from the under side should be removed with a sandpaper disk or with 
hydrofluoric acid. For etching with the hydrofluoric acid the following 
method should be pursued : The face of the filling should be imbedded 
in a piece of soft base-plate wax, leaving free the porcelain that is to 
enter the cavity. A drop of hydrofluoric acid is then placed upon the 
porcelain and left there for about five minutes, when wax and porce- 
lain may be washed in water and the filling removed from the base 
plate. The under side will be frosted and the cement will adhere to it 
fairly well, but not so well as though efficient grooves had been obtained. 

The filling and the cavity should next be washed in alcohol and 
thoroughly dried. The rubber dam may often be put on with advan- 
tage just before the filling is inserted, although the thorough dryness 
of the tooth thus obtained will at first tend to make the filling appear 
too dark. 

In a buccal or labial cavity, where no force of mastication is to 
be withstood, the transparent cellulose cement may be advantageously 
used. If this cement proves to be durable and sufficiently adhesive it 
will be a great desideratum, for a translucent insoluble cement is the 
one thing lacking to make porcelain fillings practically perfect; but 
great care should be observed in its use. The dried cavity, well under- 
cut, should be filled with the cement. The cement should then be 



THE PORCELAIN INLAY. 385 

painted all over the under side of the porcelain filling, so that the under- 
cuts may be well filled. These coatings should then be allowed to dry 
to the consistence of a thick jelly, when the filling is put into the cavity 
and ironed into place with a hot instrument. The cement sets hard 
only through evaporation of the solvent, and if the filling is too soon 
inserted it will act as a stopper, preventing the hardening of the cement. 

Where great strain is brought to bear upon the filling, or where the 
cavity is not deep enough to warrant the use of any but the most 
adhesive cement, oxy phosphate of zinc should be used. The rubber 
dam should be applied wherever practicable. The filling and cavity 
should be carefully undercut and dried in alcohol. Creamy, slow-set- 
ting oxyphosphate of zinc, corresponding in color as nearly as possible 
to the tooth, should then be placed in the cavity, and the filling, picked 
up by means of a little cement on the spatula, be pressed home. The 
porcelain should be held in position for a minute or two until the oxy- 
phosphate has lost its elasticity ; for, however perfectly the porcelain 
filling may have been fitted, if it does not go accurately into place the 
edges will be as imperfect as though an ill-adapted matrix had been 
used. As before mentioned, a creamy, slow-setting cement is essential, 
and up to the present time the Harvard cement seems best to satisfy 
these requirements. When the filling is finally in position the setting 
of the cement may be hastened by a blast of hot air or a hot instru- 
ment applied to the porcelain. When the cement is wiped away and 
the tooth cleaned, paraffin or varnish should be flowed over the filling, 
in order that the cement may set for six hours before it is exposed to 
the action of the saliva. On the following day the edges may be 
ground with an Arkansas stone or polished with sandpaper. It is 
better for finishing that the edges should be a little too low than too 
high. If, however, the porcelain is too high it can be ground down 
and still give good results ; but the original gloss is in most cases to be 
preferred. Having described the general operation of putting in a 
porcelain filling, a few cautions may not be out of place before describ- 
ing the special operations. 

A filling smaller than a pinhead should not be attempted, as good 
edges can hardly be obtained. Simple circular cavities without com- 
pound curves in the margin frequently require only one burnish, 
especially if they be small, as the contraction of the fused porcelain is 
often less than the probable personal error of the operator. 

Labial cavities should be made deep if good color and adhesion are 
desired. A bar of porcelain running into the tooth makes a much 
stronger anchorage than a platinum pin, as the platinum may stretch 
and it always tends to weaken the substance of the body. 

In large contours excessive contraction may be avoided by adding one 

25 



38 6 RESTORATION OF TEETH BY CEMENTED INLAYS. 

part in four of a colorless high-fusing powder to that part of the mixed 
enamel which is to be used for the first baking. The unfused particles 
extend across the matrix in every direction, making what is practically 
an internal investment. The slight lightening thus occasioned is 
entirely overcome by the second coat, and the proper contour is obtained 
in fewer bakings. When handling small fillings, the pliers and cavity 
may be advantageously kept wet up to the time of insertion, as capillary 
attraction will prevent the filling being dropped and lost. To place a 
tiny filling on the operating-case in the same relative position that it 
will take in the tooth prevents mistakes as to which side should go in 
first. 

In addition to the classification — labial, buccal, approximal, contour, 
etc. — porcelain fillings are to be considered in regard to their position 
in the mouth, viz. fillings that keep their color when cemented into 
place, and those that will be darkened by the consequent shadow. Unless 
these classifications are understood, many a well-matched porcelain inlay 
will end by appearing dark and unsightly in the mouth. Color varia- 
tions are met similar to those that are seen upon examining a piece 
of window-glass. The surface may be nearly colorless while the edge is 
dark green. The color of porcelain fillings is dependent upon the per- 
fection with which the light is reflected to the eye of the observer. For 
instance, in a perfect light, yellow porcelain is yellow, because all of the 
other rays that make up light are absorbed and only the yellow are 
reflected to the eye. If the light be gradually decreased, fewer yellow 
rays will be reflected, and the color will become darker ; when there is 
no light reflected the porcelain will appear black. The more perfect the 
front and side lights in porcelain fillings the less will be the shadow 
variations in color. Take, for example, a simple labial cavity, as illus- 
trated in Fig. 367. If this extend into the dentin sufficiently deep to 
prevent the color of the oxyphosphate of zinc or of any other cement 
shining through it, the correct color of the porcelain will be given. 
If, however, we place this well-matched material on the approximal 
surface of the tooth, as in Fig. 368, with an adjacent tooth shutting 
off direct reflection, and thus allowing only indirect rays to meet the 
eye of the observer, the color will be lost in shadow, and from having 
been a perfect match, or nearly so, the shade will assume a dull lead 
color. Also, if in Fig. 367 the labial cavity should penetrate entirely 
through the tooth, through the palatal enamel, the inlay would present 
a problem of almost insurmountable difficulty ; for nearly all of the 
direct rays would pass through it and would be lost in the shadows 
of the mouth, while the side lights would be shut off by the non- 
transparent but necessary zinc cement. This difficulty may be over- 
come by placing two fillings, one on the palatal and one on the labial 



THE PORCELAIN INLAY. 387 

surface. The oval inlay running through the entire tooth substance is 
mentioned only as an illustration of the greatest amount of color varia- 
tion to be met with ; and the nearer that a porcelain inlay approximates 
to this condition the greater will become the tendency of the color to 
be lost in shadow. 

Take, for further example, the two fillings shown in Fig. 369. In 
each illustration the fillings go evenly through the labial and pal- 
atal walls of the enamel, and yet if both fillings are made of material 
that matches the tooth substance the corner inlay will look well, while 
the halfmoon-shaped filling will be dark. If, however, b does not go 
through the palatal wall and the cement extends entirely behind it, its 
color will be nearly, if not quite, as good as that of the corner, it 
having almost assumed the classification of the simple labial cavity 
before mentioned. The difference in the shades of these two fillings 
may be explained as follows : The corner (a) is illuminated by side 
light from the cutting edge, while the halfmoon-shaped filling (b) is 
shut in on four sides, on three by cement and on the fourth by the adja- 
cent tooth. It must be further noted with reference to the corner (a), 

Fig. 367. Fig. 36S Fig. 369. 

Y» ><r 






that if it is looked at from directly in front, or from the direction of 
the arrow X toward the cement, the color will be good ; if, however, 
it is looked at away from the cement, as indicated by the arrow Y, the 
color will be lighter or darker according to the intensity of the light ; 
but the true color will not be seen. This, however, is not a serious 
objection, as the filling is usually seen from directly in front, and the 
occasional side views are equally divided between good and bad lights. 
We may, therefore, feel that a corner inlay which does not include 
more than a third of the tooth's cutting edge is an inlay favorable to 
the obtaining of a good match. Buccal fillings in bicuspids and molars 
are as easily matched as the simple labial cavities, for they come under 
the same conditions of light reflection ; but all approximal inlays, from 
the posterior surface of the canines back to the molars, show the same 
falling off in color, and unless allowance be made for this falling off 
disheartening results will be the outcome of otherwise careful work. 
The greater the slope of the cavity floor into the mouth the greater 
will be the shadow variations, as in Fig. 374 ; the greater the slope out- 
ward the less will be the shadow variations. 



388 RESTORATION OF TEETH BY CEMENTED INLAYS. 

Those not affected are simple labial cavities, corners of centrals and 
laterals, cusps of canines, bicuspids, and molars. 

Those most affected are tips of centrals and of lateral incisors, and 
approximal and halfmoon-shaped cavities running through the palatal 
enamel. The broader the adjacent teeth the greater will be the shutting 
out of light and the consequent darkening of color. Tips of central and 
lateral incisors running entirely across the tooth are so subject to the 
shadow variations from cross light, side light, top light, and bottom 
light, that the restoration of more than a third is not advisable. When 
half of a tooth has been carefully matched and cemented into place, the 
tip may look very well in good daylight, but at night it may turn 
dark ; also in an artificial light shining from above the tooth and 
cement line show very dark while the porcelain seems snow-white. In 
all such cases, whenever possible, a portion of the tooth should be 
allowed to run down to the cutting edge. 

And now let us consider how we may partly conquer these shadow 
variations. Halfmoon-shaped cavities, as in Figs. 368 and 369, may be 
filled on the palatal wall with gold, an absolute match thus being made 
possible. A porcelain tip may be built up as two corners, to avoid the 
side lights ; but generally all attempts to antagonize shadow variations 
will result in an effort to lighten the fillings, so that the shadows 
will be overcome. This lightening is now quite possible, for experi- 
ments indicate that an addition of from one-tenth to one-fifth of oxid 
of tin to the ordinary white enamel gives a white so dense as to be 
practically the reverse of shadow. If, therefore, we have a filling half- 
moon-shaped or approximal, we should first match the porcelain tooth 
as though it were a simple labial cavity ; then by adding to this paste 
one-fourth to one-third of the dense white powder mentioned above 
we shall find that, if the colors have been properly mixed, the filling 
when cemented into place will darken to the original color of the tooth. 

And now having described the process of using high-fusing porce- 
lain for inlays, the next consideration will be the modifications necessary 
when the low-fusing porcelain is melted in a gold matrix. The best 
of the low- fusing bodies are said to keep their color and texture in the 
mouth indefinitely, to be strong enough for all necessary wear, and to 
retain their color in fusing, — which would indicate that the low-fusing 
materials have greatly improved during the last eight or ten years. 
Porcelains capable of being melted in a gold matrix are of two classes : 
those that are sufficiently low r fusing to be melted in a bare matrix, and 
those that melt so near the fusing-point of gold as to render necessary 
the investment of the gold matrix in order to prevent its being warped 
by the fire. In porcelains of the first class the method of procedure is 
very similar to that in which the high-fusing porcelains are fused in a 



THE PORCELAIN INLAY. 389 

platinum matrix. The No. 30 gold foil is placed over the cavity mar- 
gins in a manner similar to that prescribed for the use of platinum ; and 
then, instead of burnishing or spinning it in place, it is pressed into 
all parts of the cavity by means of spunk or cotton. The metal is so 
soft and ductile that this can be accomplished in a manner impossible 
with platinum ; and it is this easy manipulation of the gold that makes 
the sole advantage of the low-fusing over the high-fusing porcelain 
bodies. The gold matrix is then teased out of the cavity. This must 
be carefully done, as, being more easily adapted, it is also more easily 
distorted than the platinum. The proper mixture of porcelain is placed 
in it, and the baking is performed exactly as with the high-fusing 
materials, the only marked difference in the working of the low-fusing 

Fig. 370. Fig. 371. 





Large cavity in molar tooth involving approximal and Showing restoration of broken lateral 
grinding surfaces. Restored by porcelain inlay. incisor by porcelain tip. 

and the high-fusing materials being that low-fusing bodies tend to 
spheroid and lose contour. This can be remedied by mixing with the 
paste a small quantity of similarly colored high-fusing porcelain. 

When such porcelains are used as require the gold matrix to be 
invested, the following additional points should be carefully observed : 
The matrix must not be torn on the bottom at all, as in such event the 
porcelain will tend to run through into the investment instead of- draw- 
ing away from the crack, as it does from a platinum matrix where no 
investment is used. The gold matrix must be dropped bottom side 
down into a paste of asbestos and alcohol, which is allowed to evaporate. 
Then the porcelain may be flowed into the matrix little by little, to 
minimize warping. 

The method described by Dr. J. Leon Williams 1 is as follows : 
" The thinner the gold can be used, the more perfect the fit of the 
finished inlay. A proper set of instruments for shaping the gold form 
and for manipulating the porcelain paste is an important matter. I 
have devised for these purposes the set of instruments shown in Fig. 
372. They are all double-end instruments. Nos. 1, 2, 3, and 4 are 
designed for fitting the gold form to the cavity, while Nos. 5 and 6 are 
for manipulating the porcelain paste. The gold should be cut out to 
represent roughly the shape of the orifice of the cavity, but consider- 
1 Dental Cosmos, November 1899, vol. xli. p. 1087. 



390 RESTORATION OF TEETH BY CEMENTED INLAYS. 



ably larger. Fig. 373 shows the proper shape for such a cavity as is 
shown in Fig. 374 at a. It will greatly facilitate the shaping of the gold 



Fig. 372. 




f% ! 



form if a notch be cut out of the gold as shown in Fig. 
373, and at the same time decrease the chances of break- 
ing through the gold in forcing it into the shape of the 
cavity. It should first be introduced into the cavity with- 
out annealing. The cut edges will then slide over each 
other as the centre of the gold is forced to the bottom of the 
cavity. . . . Then, with the cotton or spunk tightly packed 
in the cavity, take instrument No. 2 and most carefully 
burnish the gold around the entire edge of the cavity. This, 



THE PORCELAIN INLAY. 



391 



instrument will be found well adapted to reach every part of the margin. 
It will generally be found best to hold the cotton-wool back a little 
from the margin of the cavity when one is burnishing, with an instru- 
ment held in the left hand, and with this instrument (preferably a ball 
burnisher) also press the cotton-wool well into the cavity. This holds 
the gold form well in place and prevents rocking while the edges are 
being burnished. 

" Most operators have found the removal and imbedding of the gold 
form to require the most delicate manipulation, and by the methods 
heretofore described one is never quite certain whether or not this part 
of the operation has been successfully performed until the inlay has 
been completed and tried in place. All of this uncertainty may be 
avoided by the following procedure : Slightly warm and roll up in the 
fingers a small ball or pledget of hard white wax, such as is supplied 
for crown- and bridge-work. The ball of wax should be just a little 
larger than is necessary to fill the cavity completely; that is to say, it 
should slightly project over the margin of the cavity all round. The 
wax should be quite stiff when introduced into the gold form as it lies 
in the cavity of the tooth. Now take the broad, thin burnisher, shown 



Fig. 373. 



Fig. 374. 





Sheet of gold or plat- 
inum, notched and 
ready for adaptation 
to cavity. 



Right superior central, showing two large approximal cavities 
to which access is obtained by cutting freely from the lin- 
gual walls : a, tooth with cavities prepared ; b, porcelain 
inlays for same ; c, tooth showing lingual surface ; and d, 
labial surface after cementing of inlays. 



in No. 4, Fig. 372, and press the ball of wax firmly into place. To pre- 
vent the burnisher from sticking to the wax, it should first be dipped 
into French chalk or pulverized soapstone. In such cavities as are 
shown in Fig. 374, at a, broad polishing tape, dusted with French 
chalk, may be used for pressing the wax ball into place ; but great care 
should be exercised not to pull the tape the least in one direction or the 
other, as one would do in polishing a filling. This would rock the gold 
form and mar the fit. The pull should be steadily and equably from 
both ends of the tape, the object being to press the wax everywhere 
firmly over the edges of the cavity. A stream of cold water should 
now be thrown on the wax, and then the wax and gold form should 
be quickly removed. If this part of the operation is done with ordinary 



392 RESTORATION OF TEETH BY CEMENTED INLAYS. 

care, the finished inlay will always be found to fit perfectly. To facili- 
tate the quick removal of the form, care should be taken to prevent 
the wax overlapping the gold much at any point outside the margin of 
the cavity. To prevent this and also to assist in securing proper imbed- 
ding of the gold matrix it is well to let the margin of the gold project 
as much as possible beyond the edges of the cavity. 

" The matrix may now be imbedded without the slightest fear that 
its shape will be changed. For imbedding material I use plaster and 
marble-dust. When the investment is sufficiently hard the wax is thor- 
oughly melted out with a stream of boiling waters The investment is 
then dried and brought to a full red heat with the blowpipe. It 
is then allowed to cool, and is ready for packing. Now, the first step 
in the packing of the porcelain paste is the all-important one to prevent 
the porcelain shrinking away from the walls of the matrix. This may 
always be accomplished easily with porcelain of any make if the follow- 
ing instructions are carefully observed : Mix the porcelain paste to the 
consistence of soft putty, and with the upper point shown in No. 6, Fig. 
372, place a ring of this putty around the entire circumference of the cavity, 

Fig. 375. Fig. 376. 





a b c 

Showing bicuspid with cavity involving approxi- Canine tooth showing at o, large cavity, and 

mal and grinding surfaces : a, tooth with at b and c, large porcelain inlay restor- 

/ cavity prepared ; b, porcelain inlay ; c, inlay ing contour of tooth, 

cemented in place. 

leaving the centre quite free or empty. In melting a porcelain paste it 
naturally shrinks toward the largest mass of its own body, or toward 
the centre of the mass. If, then, this centre be removed we should 
naturally expect the mass to shrink toward the circumference, and this is 
precisely what happens when manipulated as directed. The matrix 
always comes out from the first baking with the porcelain everywhere 
firmly melted to the walls of the matrix. Nor will it start from this 
position at any subsequent baking unless it is very much overheated. 
"After each packing of the porcelain paste, a small camel Vhair brush 
with a fine point should be moistened (this is best done by drawing it 
between the lips after the manner of water-color artists) and drawn 
around the margin of the matrix to remove all overhanging particles of 
the paste. If this be not done, the margins of the inlay will often be 
found ragged, and a perfect margin is the most essential feature of a 



THE PORCELAIN INLAY. 393 

porcelain inlay. If gum-water be used for mixing the paste, it will be 
found necessary to remove these overhanging particles with great care, 
as the tendency naturally is for the gum-water to cause the particles of 
powdered porcelain to stick to the gold or platinum margin of the ma- 
trix. In building up the inlay for restoring lost corners of teeth and for 
general contours the work will be much facilitated if, after the first 
baking has been carried through as above described, to secure perfect 
union with the walls of the matrix, a small piece of solid porcelain be 
placed at the point representing the highest point of the contour of the 
inlay. These pieces of porcelain may be made by crushing old porce- 
lain teeth in an iron mortar. Care should be taken to use a piece small 
enough so that the outer edge will not show through when the inlay is 
completed. Corners like the one shown in Fig. 376 may be produced 
in this manner without much difficulty. " 

Dr. Williams's method of separating the gold matrix from the porce- 
lain, and grooving the inlay and cementing it into the cavity, need not 
be dwelt upon, the subject having already been fully discussed. 

In summing up the advantages and disadvantages of the high-fusing 
and low-fusing bodies it will be seen that the advocates of the low-fusing 
materials claim the sole point that gold is more easily adapted as a 
matrix than platinum ; while the others claim that porcelains of high- 
fusing bodies are known to be permanent, to keep their color under 
firing, to contour without spheroidal tendency, to dispense with the 
use and consequent restrictions of an investment, and to furnish a 
process so simple and reliable that fillings may be constructed with 
greater certainty of good results and with more rapidity. 

Furnaces suitable for fusing the porcelains used in inlays are of 
two classes — gas and electric. The gas furnace is usually noisy, odor- 
ous, and dirty ; but it seldom, if ever, gets out of order. On the other 
hand, the electric furnace is clean, silent, and beautiful ; but it has only 
a limited life. Even in experienced hands its wires will burn out 
and need mending once or twice a year, and with the inexperienced it 
may easily be rendered useless in a few seconds. Nevertheless, in 
spite of these drawbacks, the electric furnace is to be preferred to the 
gas, as with a little practice it can be easily mended, while the gas furnace 
is suitable only for the laboratory. The only feasible gas furnaces for 
high-fusing bodies are those which have a platinum muffle, in which the 
fusing porcelain can be thoroughly protected from the gas, for no fusing 
porcelain can keep its color if subjected to the products of combustion 
of carbon. The two most practicable gas furnaces are the Downie 
(Fig. 377) and the Midget Land. Either of these properly manipu- 
lated will fuse continuous-gum body within three minutes. They 
work on the blowpipe principle, and necessitate either a pressure- 



394 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



reservoir or labor with the foot-bellows. The electric furnaces are based 
on the principle that platinum wire submerged in fire-clay will become 
red-hot when a current is passed through it. The fire-clay stores up 
this heat indefinitely, so that any degree of temperature below the fusing- 
point of platinum may be obtained. This fusing-point is said to be 
about 4500° Fahrenheit. The best of these furnaces for the high-fusing 
bodies that require a temperature of from 2500° to 3000° F. are the 
Timme (Fig. 379), the Custer crown (Fig. 378), and the McBriar crown. 

Fig. 377. 




Downie gas crown furnace. 



Any one of these will give satisfactory results, but the Timme furnace 
has the important advantage of being made in sections which can be 
readily taken apart, thus rendering a burn-out easy to locate and mend. 
With the other furnaces it is difficult at times to find and twist together 
the fused or broken wires ; and when the break is located, it has to 
be reached by cutting down through fused fire-clay that is sometimes 
so dense as to require the use of a hammer. Should electric furnaces 
be used, it is well to have two, so that if a burn-out occur the opera- 
tion need not be delayed while the defect is being located and repaired. 



THE PORCELAIN INLAY. 

Fig. 378. 



395 




Custer electric oven No. 1. 



Fig. 379. 




Timme furnace. 



For baking the low-fusing bodies the gas outfit of Dr. Jenkins is 
neat and effective ; in fact, as a gas outfit it is almost ideal. The little 



396 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



electric oven made by Ash (Fig. 380) is perfect for low-fusing bodies, 
and wherever a current can be secured and low-fusing bodies are used 
this little furnace is to be strongly recommended. Its only drawback 
is that it cannot be mended, and that if a burn-out occur it must be 



Fig. 380. 




Ash electric oven. 



sent to the manufacturer for a new coil of wire. It has not sufficient 
power to melt the high-fusing bodies quickly and well. 

The Gold Inlay. — As previously said, the gold inlay has practi- 
cally perfect edge strength, and therefore is to be preferred to the 
porcelain inlay in the back of the mouth, where its color is no objection 
and where its power of resisting mastication is of prime importance. 

The following method of making gold inlays is the one advocated by 
Dr. W. V. B. Ames, of Chicago : 

a The gold inlay is especially useful in compound approximal cavities 
of bicuspids and molars. There must be ample separation. As in the 
case of porcelain, there should be excavation, both to prevent decay and 
to permit the easy removal of the matrix. 

" Taking, for example, an occluso-approximal cavity of a soft molar 
or bicuspid where a gold or amalgam filling has failed : in such a case 
decay has usually extended laterally, one side or both, necessitating 
the cutting away of the side walls to such an extent as to leave very 



GOLD INLAYS. 



397 



little support for the filling at the cervical margin. The fissure of 
the occlusal surface must then be opened thoroughly to the end for 
anchorage, and the entire margins of the cavity be excavated until they 
are strong, smooth, and sharp. When practicable, an impression of 
the cavity may be taken in modeling compound and run out in plaster 
or oxyphosphate of zinc. To this the matrix, made of pure gold No. 
36 B. & S. gauge, can be approximately fitted and trimmed, avoiding 
much laceration to the gum. The matrix should be, however, finally 
burnished to fit the tooth cavity. Then 22-carat gold solder should 



Fig. 381. 



Fig. 382. 



Fig. 383. 



Fig. 384. 




be flowed into the hollows of the occlusal surface, running off into 
the fissure. A coating of whiting placed on the outside of the matrix 
will prevent the solder from running over the edge and destroying the 
fit. Then it must be cooled, washed, and replaced in the cavity for 
further burnishing. When the occlusal groove is nearly full of solder, 
a small globule of pure gold should be placed, as in Fig. 381, a, to serve 
as a guide for the contour, which must be shaped up about the pellet 
with crystal gold or foil, into the interstices of which 22-carat solder 
is to be again flowed. 

" In the efforts to obtain anchorage on the occlusal surface punctures 
or tears frequently occur. Gold foil can be inserted into these, which 
when filled with solder afford excellent retain- 
ing pins (see c, Figs. 383 and 385). , , F ^' ^ 

" Where sufficient anchorage is easily ob- 
tained, as in pulpless bicuspids and molars, a 
dowel or small gold bead may be soldered to 
the gold foil, and adjusted to the pulp cavity, when the first start in the 
formation of the matrix is made, as in d, Figs. 384 and 385.'' 

Some dentists restore the tips of abraded frt nt teeth by burnishing 
pure gold over the surface, running little dowels up on each side, so as 
to avoid the pulp chamber, and finally moulding the contour with 22- 
carat solder, gold foil, and spongy platinum. 




398 



RESTORATION OF TEETH BY CEMENTED INLAYS. 



Dr. C. L. Alexander's method 1 is described by its author as fol- 
lows : " My method consists in detail of burnishing platinum over the 
surface to be restored; the holes for retaining posts having already been 
made, can easily be located and the posts adjusted therein. Then by 

Fig. 386. 




Showing details of the process for making cast rilling for incisor: a, pest with plate adapted; 
b, restored contour in wax ; c, the contour invested ; d, cast contour detached ; e, e, the 
finished restoration. 

heating a little modeling compound over a spirit lamp, and pressing it 
firmly down over the surface and allowing it to cool, we can remove the 
platinum sheet and posts in correct relation to each other. We now 
invest and solder the posts with pure gold. The piece is again placed 
upon the tooth in the mouth, and after carefully trimming and rebur- 
nishing an impression is taken, and when an occlusion is needed it 



Fig. 387. 



Fig. 388. 





Restoration of bicuspid 
by cast filling. 



Front and back view of an incisor restoration, and cast 
filling for molar. 



is made at the same time by the patient closing the teeth together 
before the impression material has become hard. The metal founda- 
tion will be drawn out by the impression compound when it is removed 
from the mouth. Each side of the impression thus secured is filled 
with any good investing material and placed in an articulator. After 
heating and removing the impression material, the contour of the tooth 
may be restored by building up with wax. Over the wax surface thus 
1 Dental Cosmos, October 1896, vol. xxxviii. p. 850. 



GOLD INLAY— A HARD-RUBBER INLAY. 



399 



formed gold or platinum foil is burnished; if the former, it should be 
very heavy, say No. 60. A suitable portion of the wax being left 
uncovered, the work is cut away from the model and invested, with the 
exception of that part of the wax left uncovered by the metal. Through 
this opening the wax is boiled out, leaving a matrix lined with metal, 
which acts as a carrier for the fused gold ; 20- or 22-carat gold solder 
should be used for this purpose. When pure gold is used, of course 
the matrix must be lined with platinum throughout. When removed 
from the investment, the casting is finished and cemented to its position 
in the tooth. 

" In bicuspids and molars it will frequently be found more con- 
venient to stamp up the cusps, using pure gold, 35 gauge." 

The pieces made as described by Dr. Alexander may be used as 
abutments for bridge- work. The gold inlays are, of course, to be 

Fig. 389. 




Foil matrix invested. Cast filling for molar. 



•cemented into place with great care as regards asepsis, dryness, and 
apposition. They have a great advantage over the porcelain inlays in 
that their edges may be burnished into place while the cement is soft ; 
and therefore when they are being given their final polish with the 
sandpapar disk the disk should always be run toward the margins, so 
that a feather edge may be formed, which, with the burnishing men- 
tioned, may make an almost absolute joint possible. 

A Hard-Rubber Inlay. — Some dentists advocate making cemented 
inlays of hard rubber approximating the tooth in color. These inlays 
are feasible only where a perfect impression can be readily taken of the 
oavity, the filling being then made by the method usually followed in 
vulcanite work. The rubber inlay is noted only as a curious fact, and 
is not enlarged upon or recommended, as its color is not equal to porce- 
lain, nor is its edge strength equal to that of gold. As we have not 
only other materials that will produce better results, but also materials 
that can be manipulated in the time required merely for the vulcanizing 
of the rubber, it does not seem advisable to enlarge upon a process that 
appears to have no practical value. 



400 RESTORATION OF TEETH BY CEMENTED INLAYS. 

MAKING MATRICES UPON MODELS FOR PORCELAIN INLAYS. 

There are many who take impressions of the cavities intended for 
porcelain inlays, which impressions are run out in plaster or oxyphos- 
phate of zinc. On the models thus obtained the matrices are formed, 
and the porcelain fillings finished according to shades selected when the 
impression was taken. This has the advantage of saving much time for 
the operator, as the work of construction may be done by an assistant 
in the laboratory. As good results are claimed, the process should be 
given a fair trial ; but on theoretical grounds the expansion of the 
plaster, or the contraction of the oxyphosphate of zinc 1 used for the 
mould would tend to cause inaccuracy in adaptation of the edge. 
Most inlay workers find it sufficiently difficult to get perfect adaptation 
when the matrix is burnished to sharp enamel edges, and, except in 
labial cavities, to get the exact contour. Also, the colors often require 
such nice calculation that an assistant, not having seen the mouth, 
could hardly mix them satisfactorily. While good results have been 
obtained by giving the matrices for filling to an assistant especially 
trained in the art of fusing and mixing the porcelains, thus proving 
that such time-saving methods are practicable, the average dentist 
should not attempt the art of inlays with the idea of saving time ; 
probably there will always be sufficient factors for failure if he works 
directly from the tooth cavity and gives his entire personal skill to 
the completion of the filling. With porcelain inlays the question of 
artistic color effect is paramount, and only through the most subtle 
discrimination can the best results be obtained. 

1 Wet oxyphosphate of zinc usually expands ; dry oxyphosphate usually contracts. 



CHAPTER XYI. 

THE CONSERVATIVE TREATMENT OF THE DENTAL PULP- 
DEVITALIZATION AND EXTIRPATION OF THE PULP. 

By Louis Jack, D. D. S. 



As the dental pulp by its supply of nutritive pabulum maintains 
the vitality of the dentin and increases the resisting power of the tooth, 
it is important when this organ becomes exposed to agencies which 
threaten its destruction, to attempt its preservation when the condi- 
tions are favorable to that object. A further reason for maintaining 
the vitality of the dentin is that when the pulp becomes devitalized the 
loss of cohesive force which occurs as a consequence leads sooner or 
later to the fracture and early loss of the tooth — this final result being 
delaved in proportion to the inherent strength of the tooth and the 
period of life at which devitalization takes place. 

The treatment of teeth when the pulp has been approximately 
reached by the invasion of dental caries has been previously consid- 
ered (Chapter VII.). Here will be set forth a rational line of treatment 
when the carious action has encroached upon that organ. 

Normal Characteristics and Pathological Tendencies of 

the Dental Pulp. 

The minute anatomical elements of the dental pulp are given in 
Chapters II. and III. The salient features of these elements which 
have to be kept in view in connection with treatment are — 

(1) The minuteness of the apical foramina, which restricts the efferent 
circulation when the vascular phenomenon known as " determination " 
occurs. 

(2) The ultimate nervous distribution immediately beneath the odon- 
toblastic layer, forming a plexus which renders the whole surface of the 
organ highly sensitive when the blood supply is increased as the effect 
of irritation. 

(3) The arrangement of the capillary circulation in loops which arise 
from the vertical vessels. This relation of the vessels lessens the tend- 
ency to inflammatory diffusion. 

2fi 401 



402 CONSERVATIVE TREATMENT OF THE PULP. 

(4) The absence of lymphatics, which deprives the pulp of the power 
to remove inflammatory effusions or to convey insoluble medicaments. 

It should be noted that the pulp in a normal state is not a highly 
sensitive organ, but is rendered exquisitely so by the irritation from 
external chemical and infectious influences incident to its exposure. 
And it is under all conditions so extremely impatient of compression 
that a severe shock of that kind renders recuperation nearly impossible. 
This is probably due to the liability of disconnection of the pulp with 
its walls at some point on account of its feeble attachment to them. 

The pathological tendencies of the pulp under irritation are — 

(1) To hyperesthesia. 

(2) To circumscribed hyperemia under slight irritation. 

(3) To congestion or mechanical hyperemia under increased irrita- 
tion which terminates at length in stasis by the restriction of the 
circulation. 

(4) To proliferation of the deeper tissues as the result of latent con- 
gestion attended by fatty degeneration of cells and the development of 
dentinal nodules — pulp stones. 

An important consideration connected with the treatment of the 
pulp is the indication presented by a state of the teeth designated as 
the " temperature sense." This is a variable condition with different 
individuals, some being able to apply the coldest water in the mouth 
and to crunch ice without pain, whilst others whose teeth are sound are 
disturbed if cool water is brought into direct contact Avith these organs. 
When irritation of the pulp occurs the temperature sense is exaggerated 
in the individual tooth. This variation from the normal, as determined 
by a comparative test of the sound teeth, becomes an important diag- 
nostic indication, as will appear later. 

A further pertinent consideration bearing upon the various condi- 
tions of the exposed pulp, as shown by the symptomatology, is here in 
place. It has already been indicated that when the exposure of the pulp 
to irritation has been slight — that is, where this organ has been measur- 
ably protected from exterior influences by the covering layer of incom- 
pletely decalcified dentin — the pulp is ordinarily but slightly affected. 
When the denudation has become complete and the amount of pulp 
surface in contact with the carious matter has become considerable, 
and further, when by the solution and displacement of the carious 
matter the influence of the contents of the mouth is direct, the disturb- 
ances of the pulp become progressively increased. In the light of pres- 
ent knowledge of these injurious influences the causes of their operation 
must be attributed to infection of the pulp by the various minute organ- 
isms which have their habitat in the mouth. The pulp tissue becomes 
infected in the degree to which it is exposed and in proportion to its 



PATHOLOGICAL TENDENCIES OF THE PULP. 



403 



Fig. 390. 



power of resistance to the pathogenic character of these forms of life. 
It is axiomatic that the activity of inflammatory processes is usually in 
proportion to the degree and the kind of infection. Therefore it must be 
held here as elsewhere in surgical procedures that the existence of infec- 
tive influences and their control have to be kept clearly in view. 

This consideration enables us to understand the causes which render 
conservative treatment inoperative, in cases in which there has existed 
for a considerable period the opportunity for active invasion of the pulp 
by micro-organisms. When these deleterious influences have long con- 
tinued, the deeper tissues of the pulp, as before stated, become involved ; 
the chief factors producing the disturbed state eventuate in a suppura- 
tive condition. This state of the organ clearly indicates invasion by pyo- 
genic germs, the inflammatory processes attending this condition being 
superinduced by the peculiar irritation caused by the infection. This 
results in some instances in stasis followed by gangrene ; in other cases, 
where the arterial tension has not been great, in suppuration. The cha- 
racter of the suppurative process, rarely, is a circumscribed abscess of 
the pulp, the more common form being by 
progressive and destructive ulceration of 
the organ. 

Fig. 390 (after Arkovy) shows the 
phenomenon of invasion of the pulp by 
micrococci. 1 

In the treatment of an organ which 
cannot be brought under ocular inspec- 
tion, the chief guides to determine its state 
are the apparent conditions — viewed in con- 
nection with the symptomatology of the 
case under treatment. 

The above-stated anatomical relations, 
physiological qualities, and pathological tendencies have an interesting 
bearing upon conservative treatment of the pulp. 

Exposure of the Pulp. — As an indication of the tolerance of the 
pulp to the approach of caries it is a common experience that after 
solution of the enamel has taken place, caries of the dentin proceeds 
until the pulp is nearly reached by the destructive process with little or 
no signs of irritation, as evinced by pain, appearing. It is the excep- 
tion that even persons of high nervous sensibility are cognizant of the 
influence of the carious process upon the pulp previous to actual 
encroachment. 

In the earlier stages of exposure the elements of the organ involved 

1 In this connection see Micro-organisms of the Human Mouth, by W. D. Miller, pp.. 
293-295. 




Invasion of pulp by micrococci.. 



404 CONSERVATIVE TREATMENT OF THE PULP. 

are its peripheral nerve filaments, which are hyperesthetic from the 
hyperemic state of the organ immediately adjacent to the point of 
encroachment. At this stage the pulp becomes impatient of cold, and 
may indicate the nature of the lesion by reflex pain in other branches 
of the trigeminus. Later on, unless these conditions are subdued by 
treatment congestion of the organ takes place, when objective symp- 
toms in the organ itself may be elicited. This is shown by some sore- 
ness upon percussion, accompanied by much pain on the application of 
heat. 

These indications point to a greatly increased blood supply. Dila- 
tation of the arterial vessels of the apical region occurs, and the blood 
being unable to enter at the foramen is distributed to the peridental 
membrane. These manifestations indicate that the point of danger 
has approached. Soon thereafter congestion becomes so far estab- 
lished that prospect of successful conservative treatment vanishes. 

When patients are under frequent observation and have regular and 
periodical care taken of the teeth the pulp exposures which occur should 
be found in the hyperemic state, and if placed under treatment early 
after the carious action has approached the pulp, the prognosis should 
be favorable. But when neglected cases appear the history of which 
is obscure, and where the patient is forced to seek relief by the occur- 
rence of objective symptoms as narrated above, accompanied by local 
pain and pulsation, the indications point to devitalization and extirpa- 
tion as the suitable recourse. 

The exposure of the pulp is often discovered in the treatment of 
ordinary cavities in a somewhat unexpected manner, no indications 
appearing until the part is uncovered ; or a variety of subjective or 
possibly objective indications may be elicited which plainly point to 
this condition. 

At the commencement of the treatment to restore the lost tissue 
in any given carious tooth, except in very small cavities, the proba- 
bility of encroachment upon the pulp should be a supposition, and each 
step should be made with reference to this probability. The destruc- 
tion of the dentin is frequently surprisingly deep, or the cornua of the 
pulp may be acutely pointed and liable to be unexpectedly encountered. 
Therefore, in what may seem simple cases, cautious approach should be 
made toward the bottom of the cavity. 

Method op Opening the Cavity. 

The opening of the cavity should be effected by instruments 
which will not easily enter it, and the softer caries removed in a 
manner which will not induce pressure of the carious matter upon the 
pulp. For this reason, in the removal of the caries the excavation 



METHOD OF OPENING THE CAVITY. 405 

should be first carried on at the sides of the cavity, and also along the 
margin of the cervical wall in approximal cases. Then the carious 
matter nearest the pulp should be carefully peeled off without pres- 
sure and without irritation. In this manner a pulp may be uncov- 
ered and the cavity cleansed of carious matter without contact being 
made with the pulp. To do this is the acme of skilful preparation. 

The instruments for removing caries should be of thin edge, very 
sharp, and always having cutting surfaces which are rounded, since 
angular or square-ended excavators are liable to make exposures un- 
necessarily. It is important that the direction of movement of the ex- 
cavators should be from the cervix toward the occlusal part — in other 
words, by drawing cuts instead of pushing ones. The diiference in the 
excitement of pain between these two methods of cutting is surprising, 
and can only be appreciated by those who have experienced the com- 
parison upon their own teeth. The probable reason for this is that the force 
of the pushing cut is necessarily greater, and this may induce com- 
pression of the caries or of fluids against the pulp. It causes more 
pain at the moment, and cleansing in this manner is followed by greater 
after-irritation. Patients will at the time complain of reflected pain 
being caused by incorrect manipulation. 

It is obvious that every mode of procedure which increases the local 
irritation in the preliminary procedures of a pulp treatment must be 
deleterious in its results. The danger of making accidental exposures 
and of forcing the instruments upon the pulp are increased under push 
cutting. It is also clear that the use of burring instruments upon the 
pulp wall of cavities is questionable, since the infliction of some com- 
pression by excavating in this manner is nearly unavoidable. 

Here an interesting question appears : A cavity may be sufficiently 
deep to cause an exposure ; it has been carefully cleansed of caries, and 
the cornua are not apparent. It is then necessary to determine whether 
there is a real but minute exposure or whether there is a safe amount 
of healthy dentin to protect the pulp beneath the stopping material. 

One method is to cross-hatch the cavity by a very fine explorer. 
This is effected by holding the instrument very lightly and passing 
it gently over the surface in parallel lines in two directions. If the 
pulp has been reached, the instrument at the point of encroachment 
will lose its resistance or will drag the point of the cornu, as the case 
may be. 

While there may be no visual evidence of exposure, the certainty of 
it is frequently shown during the preparation of the cavity or the test- 
ing by a peculiar expression of the face of the patient, different from 
that manifested by the cutting of the most exquisitely sensitive dentin. 
This change of the countenance, accompanied by a slight start of the 



406 CONSERVATIVE TREATMENT OF THE PULP. 

features, may occur without the recognition of pain. This indication 
sometimes appears previous to the removal of all the caries ; it is then 
probably caused by some tension of the apex of the cornu produced 
by the disturbance of the carious dentin. 

The Diagnostic Value op the Reaction of the Pulp to 

Thermal Tests. 

Allusion has been made to the eifects caused by reducing the tem- 
perature of the teeth. To make this subject clear it is necessary to con- 
sider the reaction of the dental pulp to thermal changes in its states of 
health and of disease. 

The normal rate at which the pulp of sound teeth reacts to cold 
applications varies with different persons from 22 to 66 degrees F. below 
the blood heat, the reaction to heat varying from 20 to over 55 degrees 
F. above the blood temperature, these tests being the extremes of the 
writer's observations. 

The degree of heat reaction may be designated by the -f sign and 
the cold rate by the — symbol. These ascertained extremes may be 
taken as representing the range of tolerance, in any individual case. 

The significance of ascertaining the normal rate of thermal irritation 
of the teeth is important in connection with the treatment of any case. 
When a healthy rate of + 144° - 32° F. is compared with one of + 124° 
— 76° F. this at once is apparent. In the one case, the range of tolerance 
is 112 degrees ; in the other, 48 degrees. Hence it is obvious that the 
determination of the normal rate is essential as a basis from which to 
consider the value of the thermal reaction of any given disturbed pulp. 
It is also evident that where the range of tolerance is considerable the 
probability of favorable treatment is greater than when this is small. 
Where the normal range is found to be below 50 degrees F., unless the 
other conditions are very favorable, conservative treatment of the pulp 
becomes questionable. 

The normal rate is easiest found by exposing the lower incisors to a 
continued discharge of water from a small-aperture syringe. The most 
suitable kind of syringe is that having a large aperture for charging 
and a small one for discharging. 1 

The tests are begun at a temperature of 80° F., reduced succes- 
sively by diminutions of ten degrees until slight pain follows the tests. 
The continuation of the stream of cold water is necessary to enable 
the effect to reach the pulp through the dentin. With some per- 
sons the response is so quickly shown as to indicate that the dentin 
is responsive. 

1 The best for the purpose is a modified form of the Laskey syringe. 



i 



REACTION OF THE PULP TO THERMAL TESTS. 407 

A large proportion of persons manifest distress between 40° and 
60° F. 

Intolerance of heat is determined in the same manner, except that 
it is frequently necessary to isolate the tooth by applying rubber dam, 
since the gum usually begins to be pained at 130° F. In all cases in 
which the cementum is exposed isolation is required, since the cemen- 
tum may react at slight variations from blood heat. To secure exact- 
ness in any case isolation is better than an open test. 

AVhen disturbance of the pulp occurs from the extended progress 
of caries the reaction of the pulp to changes of temperature is usually 
marked, and the variation from the normal rate is indicative of the 
degree of disorder of this organ. The response occurs to temperatures 
both below and above the normal rate. When the irritation of the 
pulp consequent upon its exposure is slight, the reaction is principally 
to cold, the degree apparently depending upon the extent of the hyper- 
emia. AVhen the reaction to heat is marked, congestion of the organ 
is threatening. 

Disorders of the pulp appear to excite other anatomical elements of 
the teeth, as is indicated by reaction to cold and heat being more 
immediate than is the case with the sound teeth. A more exact 
degree of temperature reaction may also be secured when this condi- 
tion exists. 

It is essential in making tests that a carious cavity be closed by a 
pledget of wet cotton. This is sufficient to exclude the disturbing effect 
of the hypersensitive dentin, since water is a nearly absolute non-con- 
ductor. 

Examples from practice to illustrate : 1. Cavity rate, + 110° —80°, 
when protected as above — 130° - 60°. Here the normal rate was 
+ 131° - 58°. 2. Cavity rate, + 108° - 90° ; normal rate, + 134° 
-65°. 3. Cavity, + 120° - 50° ; normal, 128° -48°. 

The following table of normal rates shows the relation between the 
point of heat reaction of the pulp and the degree of its reaction upon 
the abstraction of heat : 



+ 152° — 41° 
+ 150° — 40° 
+ 144° — 48° 
+ 144° — 32° 
-f- 140° — 48° 
j- 140° _ 46° 
+ 140° — 46° 
+ 140° — 32° 
4- 140° — 56° 
+ 134° — 58° 
4- 134° — 65° 
+ 134° — 60° 



+ 133° — 66° 
+ 131° — 63° 
+ 130° — 55° 
+ 130° — 72° 
+ 128° — 48° 
-f- 126° — 64° 
+ 124° — 76° 
+ 124° — 60° 
+ 122° — 75° 
+ 120° — 72° 



408 CONSERVATIVE TREATMENT OF THE PULP. 

The normal averages of table — 

9 cases from + 152° to + 140° 

average + 143.3° — 43.2° = 100° range of tolerance ; 
7 cases from + 140° to -f 130° 

average -f 132.3° — 62.7° = 69.6° range of tolerance ; 
7 cases from + 130° to + 118° 

average + 123° — 67° = 56° range of tolerance. 

Occult Oases of Reflected Pain. 

Cases difficult of diagnosis sometimes appear in which the question 
arises whether the pain is caused by a hyperesthetic pulp, by the influ- 
ence of malarial poisoning, or by a gouty condition. When the origin 
depends upon the two causes last named the teeth are not subject to 
thermal irritation ; also from these causes the occurrences of pain are 
not confined to the evening, as usually is the case with teeth in the 
early stages of disturbance. 

The stages of pulp exposure are divisible into three periods — (1) of 
quiescence ; (2) of subjective symptoms, and (3) of objective manifestations, 

(1) Quiescence may continue in many instances for a considerable 
period after caries has reached the pulp where the situation is such 
that the force of mastication cannot cause compression of the contents 
of the cavity. Notwithstanding constant saturation of the gelatinous 
covering, and the presence of the micrococci concerned in producing 
the caries of the dentin, excitement of the pulp may not occur. The 
fact should not be overlooked that some persons escape odontalgic 
symptoms notwithstanding such progressive alteration of the pulp tissue 
takes place as to result in gangrene of the organ. 

(2) Usually, however, after a period of quiescence of a longer or shorter 
duration there arises a train of subjective disturbances brought on by 
the continuance of chemical irritation and by the presence of fluids in 
the cavity, these influences becoming accelerated as the area of exposure 
becomes increased. The pain which occurs in this stage is reflected to 
one or more branches of the fifth pair of nerves. Flashes of pain 
occur to the teeth of the other maxilla, to the eye, or the supraorbital 
region, the most common region affected being the nerves of the ear, 
pain in this organ being probably the most general form of reflection 
which occurs. The exacerbations take place usually in the evening and 
at first entirely remit in the daytime. The pain in this stage will fre- 
quently pass away as the pulp is relieved from pressure and chemical 
irritation. 

In this stage the surface of the pulp does not present indications of 
being inflamed. From the lack of continuity of the symptoms it is 
a reasonable inference that the hyperesthesia observed in this condition 
is due to impressions made upon the point of encroachment and is con- 



TECHNICAL TREATMENT OF THE UNCOVERED PULP. 40D 

fined to the nerve fibrils distributed about the capillary loops involved, 
and thereby induces the reflected manifestations, the nerve fibrils being 
in this stage the anatomical element chiefly implicated. 

(3) Objective symptoms comprise those manifestations which, after 
the subjective ones have continued for some time, become localized in 
and about the affected tooth. These are : some soreness of the peri- 
dental membrane; extreme sensitiveness to heat, accompanied through- 
out with dull, heavy pain in the tooth, and at length pulsative 
throbs. 

This order of statement is the usual sequence in which these indica- 
tions appear. They are the result of the extension of the disturbance 
to the deeper circulatory elements of the tissue. When this condition 
appears on the presentation of a case, or when in the course of the 
treatment it becomes apparent, the prognosis usually is rendered 
unfavorable to recuperation. 

The Technical Treatment of the Uncovered Pulp. 

Accidental Exposures. — These, which happen in the preparation 
of cavities, if produced by clean (aseptic) instruments where compres- 
sion has been avoided, require but simple treatment. The pain is 
relieved by the application of tincture of calendula one part, to four of 
water. When the bleeding ceases, the point of exposure should be 
antiseptically dressed and capped in the manner to be described. 

If the injury has been slight, the cavity may be at once filled w r ith 
a metal, having regard to the strength, the placement, and the fixation 
of the cap used to defend the part from compression. Here the fixa- 
tion may be made by covering the cap with a broad block of gold foil ; 
after adapting this to the margins of the pulp wall of the cavity the 
filling may be proceeded with. In case of doubt a metal of less con- 
ductivity may be used, such as tin or amalgam. A metal filling is 
better in these cases, since the slight thermal irritation tends to the 
ultimate recovery. (See Chapter VII.) 

Treatment of Recent Exposures. — When the pulp has been fully 
uncovered, as previously described, the cavity should be washed clean 
with tepid water, be securely protected from the fluids of the mouth 
with rubber dam, dried, and lightly filled with a pledget of lint sat- 
urated with a mild disinfectant. On account of the invasion of the 
zone of dentin immediately beneath the caries by bacteria and micro- 
cocci, it is recognized that some means of sterilization must be adopted. 
This being necessary in the treatment of ordinary cavities, it is evidently 
here more demanded. On account of the impatience of the pulp to 
medication it. is important to be careful in the selection of the sterilizing 
agent. The choice should be between hydronaphthol, acetanilid, and 



410 CONSERVATIVE TREATMENT OF THE PULP. 

formalin : the first in the strength of 1 to 300 parts water ; the second, 
1 to 200 parts ; the third, not stronger than 3 per cent. 

The saturated pledget of cotton may remain in the cavity during the 
procedures of the preparation of the dressing paste, the selection of the 
cap, etc. 

When these preparations are complete the cavity should be again 
dried, the drying being finished by a few puffs of warmed air. The 
point of exposure and the adjacent dentin are now touched with lint, 
filled with carbolic acid and oil of cloves, equal parts. The effect 
of this is to coagulate to a superficial degree the point of exposure. 
This practice is largely empirical. It may be avoided in cases where 
no disturbance has previously existed ; but where there are evidences 
of irritation it seems indispensable. 

The application of carbolic acid in this manner should be for a 
moment only. As carbolic acid has a very feeble affinity for water and 
as the topical touch is but momentary, it probably does not invade the 
tissue to an appreciable degree. It will also be observed that the com- 
bination possesses anesthetic properties. 

The student will not fail to hold in view that the treatment is appli- 
cable to cases in which it is evident the pulp tissue is not under much 
irritation. The condition should be one of hyperemia of the organ and 
gives indications of- this by the existing hyperesthesia. Congestion 
should not have taken place, neither should inflammatory indications 
exist. Therefore the inference is that after the carious matter is removed 
the surface of the dentin and the point of exposure may be sterilized 
and the vital force of the pulp be given the opportunity to overcome 
whatever slight bacterial invasion may have reached that organ. Here 
the case must rest upon the well-established fact that the tissues have 
considerable power of mastering the influence of non-pathogenic germs 
as a factor in the process of recuperation. 

Treatment of Old Exposures. — In the conditions which exist 
where denudation has taken place to a considerable degree and where 
irritation has long continued, the disturbances which have arisen in 
consequence of the extension of the disorder to the larger bloodvessels 
and the attendant alteration of most of the anatomical elements of the 
pulp, the chances of establishing quiescence are slight. 

In the earliest stages of objective disturbances when the constitu- 
tional conditions are favorable an attempt may be made at conservative 
treatment after the inflammatory conditions are subdued by antiseptic 
treatment, accompanied by the use of resorbents and counter-irritation 
upon the gum. 



CAPPING THE PULP. 411 

Capping the Pulp. 

A prominent feature in the conservative treatment of the pulp is the 
means to protect it from pressure, in agreement with the established 
fact that there is no irritation so fatal to the normal functions of the 
pulp as compression, and no condition from which it recovers with so 
much difficulty as this. Therefore all means directed toward its con- 
servation must conform to the necessity of preventing the least degree 
of compression. The means employed to prevent this form of disturb- 
ance have given this method of treatment the common appellation of 
" capping the pulp." 

Another principle of equal importance connected with the foregoing 
is that the capping material should be brought into immediate apposi- 
tion with the pulp. This is for the reason that if the least space be 
permitted to exist between the capping and the exposed point this space 
will fill with effused fluids, and the putrefactive changes which take 
place in these fluids induce the formation of gases with consequent 
compression. 

METHOD OF CAPPING. 

Various methods of capping are practised, such as laying on the part 
■disks of paper or asbestos rendered antiseptic in various ways ; using 
disks of paper coated on the side to be placed next the pulp with 
" chloro-percha " or other plastic matter ; flowing over the exposed 
point a coating of oxysulfate or oxychlorid of zinc, being careful with 
the latter to use a formula of the fluid element in which the zinc 
chlorid is only in sufficient proportion in relation with the water that 
the union Avith the zinc oxid is not active. In connection with this 
method it has been common to mistakenly employ the strength of the 
fluid which is used when the formula is adapted for temporary fillings. 
When this method is used the coating is flowed over or laid in a cap on 
the pulp, and when somewhat " set " the cavity is temporarily filled 
with a more resistant material laid upon it with great care. 

With all the precautions which may be taken these dressings 
are somewhat complicated and are not applicable to small cavities or 
those difficult of access. In these cases the 
writer has generally depended upon the use Fig. 391. 

of a dressing composed of carbolic acid and ^. ^^^ 
oil of cloves equal parts combined with zinc lyP |§P 1 

Oxid to form a plastic paste of Such Consist- Weston's dental cavity caps. 

ence that when it is laid upon the pulp it will 

yield as it is adapted to the part, without producing pressure, and will 
flow out around the margins of the metal cap when this is used to con- 
vey the dressing. 



412 CONSERVATIVE TREATMENT OF THE PULP. 

The composition of the dressing is based npon the considerations 
that the menstruum is antiseptic, and possesses some anesthetic value. 
It also remains unchanged within the space and in time becomes, from 
the dissipation of the menstruum, somewhat firm in its character. The 
therapeutic action of the menstruum when combined with the zinc oxid 
is mild, and is employed for the reason that it is slowly given up by the 
oxid, and therefore makes an acceptable dressing. 

The Cap. — In all cases where metal fillings are selected it is essential 
to use a metal cap. The methods where this is used are simpler and 
better under control than when dressings are made without this appli- 
ance. The reason for this is that the avoidance of compression is more 
certain. 

The caps are best when made of platinum, for the reasons that this 
metal is a resistant material and the caps are easily formed. 

When the outer filling is to be of gutta-percha or of the mineral 
cements, caps may be formed of concave disks of pure tin. The tin 
and platinum caps are stamped from the plate by the hollow punches 
of the hardware shops, by which means various sizes of round and 
elliptical ones may be made. The effect of punching them upon the 
end of a block of wood gives the suitable concavity to meet the require- 
ments. For ordinary purposes they should be quite thin, but when 
gold fillings are made over them the thickness and the concavity should 
be such as to enable them to sustain the force applied. In cases where 
there are indications of approaching congestion, or where it is probable 
that the exposure is not recent, the dressing should have added to it a 
portion of guaiacocain. 

Placing" the Cap in Position. — Placing the cap in position is a step 
in the treatment requiring care. It should be assured that it is of suf- 
ficient size to pass well beyond the borders of the ex- 
posed organ, and in the approximal cavities it should 
cover the pulp wall of the cavity without intruding 
upon the marginal walls. If there is a single exposure 
it should be round ; if two cornua are exposed, either 
two caps should be laid or one oval one employed, as 
may best suit the case. In molars, usually, where two 
points are exposed, two caps are generally best; in the 
bicuspid, one oval one under the same circumstances. 
The cap should be inserted edgewise in such manner 
that as it is laid in place the excess of dressing may flow 
out at the margin toward the operator. This is to prevent undue 
pressure, and to avoid air being included beneath the dressing, which 
would prevent complete apposition of the dressing with the pulp. 
In cases of easy access the cap may be laid in place with fine-pointed 




CAPPING THE PULP. 413 

pliers — notably the Bogue pliers ; but in the majority of instances it is 
preferable to previously coat the convex side of the metal with wax, 
when, with an instrument adapted to the case, it may be carried into 
position and then placed in the manner described. It should next 
be pressed into position with sufficient force to bring the margins in 
contact with the dentin. Any excess of dressing should be taken away 
by light touches of an excavator, and when the cavity is to be filled 
temporarily it is better to fix the cap in place by flowing over it a little 
chloro-percha, which, when dried, prevents disturbance of its position 
in the filling procedure. 

Care should be taken that when the pulp is found exposed in a de- 
pression, as occurs sometimes in the molars, this depression should be 
filled nearly or quite to a level with the floor of the cavity by taking a 
little of the dressing upon a suitable instrument and carefully filling 
this point ; otherwise, when the cap is placed, the paste may not find its 
way into contact with the pulp. 

At the moment of placing the cap, as the paste is yielding under the 
gentle pressure of forcing the edges of the cap into contact with the 
dentin, a little pain will sometimes be observed ; but 
unless the paste is too stiff no compression of the pulp G- 393- 

should be caused. 

Filling" the Cavity. — Whether the cavity shall be 
filled temporarily or permanently depends upon the 
prognosis. This, as will be perceived, is based upon 
the constitutional conditions and the state of the pulp 

F ^ Cap in position. 

at the time of treatment. 

For those of small experience in this line of treatment it would not 
be safe to attempt the permanent stopping of the cavity, except in acci- 
dental exposures and in cases where the history of no previous dis- 
turbance can be elicited and where the thermal reaction is slight. Even 
in the latter class it is generally best to delay permanent closure by a 
conductor of heat until after an experience of a year or more with a 
non-conducting stopping. At the end of this time the filling may be 
nearly all removed, care being taken not to disturb the cap, when with 
suitable precaution a metallic filling may be inserted. 

In the majority of instances it is safest to fill the cervical part with 
gutta-percha stopping, carrying the material over the cap, and then to 
complete the filling with zinc phosphate. In this way, with an occa- 
sional renewal of this temporary work, cases may be carried forward 
from ten to fifteen years. 

They may, however, be closed permanently and safely after an 
experimental trial of five years where no irritation has appeared. 

In many instances recovery takes place by secondary deposits of 




414 CONSERVATIVE TREATMENT OF THE PULP. 

dentinal tissue the exact character of which has not been made out. 
The writer has observed a multitude of cases in practice when the open- 
ing at the point of exposure has become occluded by bony tissue. In 
some instances this has occurred in two years, in others after longer 
periods. In one instance a lateral incisor became protected by this 
formation, but in consequence of mistaken diagnosis of another condi- 
tion causing pericementitis, a drill was passed through the new tissue 
to the living pulp. This new opening healed again. In the same mouth 
another incisor also recuperated in the same manner. 

In some cases when entire quiescence has been maintained for many 
years the pulp will be found not to have undergone any protective 
changes. 

It is not remarkable, however, that pulps may remain in a state of 
quiescence for a long period, when it is considered that in slowly- 
advancing caries the pulp will often be exposed for a long time without 
the occurrence of any signs of irritation, unless, by the position of the 
mouth of the cavity, the pulp has been subjected to the pressure of 
food. 

It may be concluded that, whether the pulp becomes protected by 
secondary deposits or acquires complete quiescence, conservative treat- 
ment in these cases has considerable advantage over immediate devital- 
ization. Still, in this connection in order to avoid embarrassments the 
necessity exists for careful selection of subjects to be treated in this 
manner, and also for proper analysis of the apparent condition of the 
pulp itself. To aid in this discrimination the following summary of 
conditions should be held in mind : 

(a) Where no previous observable disturbances can be elicited. 

(b) Where the tooth has been impressed only by the application of 
low temperature. 

(c) Where, in addition, reflected pain in related parts has been 
observed. 

(d) Where the tooth has become much subject to impressions by 
heat. 

(e) Where continued objective disturbances appear, such as soreness 
to touch, or local pain of spontaneous character accompanied by pulsa- 
tion. 

Classes a, b, and c may be considered as amenable to treatment, and 
also, problematically, class d if taken early. Class e must, in view of 
the principles stated in this section, be eliminated from the field of con- 
servative treatment ; and where cases in the other divisions apparently 
amenable subsequently take on disorders coming within this classi- 
fication they usually have passed beyond the reach of palliative treat- 
ment. 



CAPPING THE PULP. 415 

It is important here to consider the influence of the physical endow- 
ments of the patient upon the conservative treatment of the pulp. For 
some persons this treatment is followed by the happiest results ; no 
intolerance of the operation appearing, and even cases somewhat un- 
promising doing well. Again, with others, any case, however simple,, 
goes down the scale to class e in spite of every care. 

The first constitutional condition favorable to success is that of 
soundness. As to what are called temperamental indications, when the 
subject is of good health, the lymphatic should alone be excluded and 
more particularly the bilio-lymphatic. These latter do not respond to- 
pulp treatment in any conditions which occur to them ; and in reference 
to their exposed pulps the probabilities are that in the sluggish condi- 
tion of the parts involved the organ is early invaded by bacteria, and 
such changes have quickly taken place in the anatomical elements of 
the pulp as to render all chances of successful treatment valueless. The 
most promising cases are those for persons of active temperaments, Avith 
good circulation, thin skins, healthy gums, and limpid oral secretions. 

After-treatment. — It is not unusual for classes a, b, and c to require 
after-treatment. For this reason close observation for some time should 
be maintained. It is presumed that the judicious operator has made 
careful selection of the cases to be conservatively treated and that he 
will early decide from an analysis of the evident conditions whether the 
prognosis is promising or not. As previously indicated, some of the 
apparently favorable cases will not yield to treatment for the reason 
that the actual condition of the pulp may not be made out. Part of 
the difficulty here is occasioned by the indefinite character of the state- 
ments of the patient, who should in all cases be instructed to return for 
consultation if painful response to cold appears or if reflected pain 
should occur. If these conditions supervene, it is a sign of needed care 
to avert increasing disturbance. 

A most marked form of reflected pain is felt in the ear, and this 
frequently occurs previous to the aggravation of the temperature reac- 
tions. So much importance should be attached to this symptom of 
pulp disturbance that the first question asked a patient appearing with 
pain, or on approaching a suspected pulp, is, Have you had any pain 
in the ear of that side? As reflection to the ear often occurs in advance 
of similar pain in other branches of the fifth pair, it becomes important 
to maintain close observation of this indication. In this state, sedation 
combined with counter-irritation is required. 

In any case where the tooth has been impressed by cold, either before 
the treatment or afterward, an application should be made to the gum 
over the tooth, of tincture of aconite root two parts, chloroform one 
part. The mode of application is important. A pledget of cotton or 



416 CONSERVATIVE TREATMENT OF THE PULP. 

muslin to cover an area of one-half by three-fourths of an inch should 
be filled with the prescription, then squeezed out nearly to dryness between 
folds of a napkin to prevent an excess flowing over the mouth and with 
the saliva entering the fauces, to which it is extremely irritating as well 
as unnecessarily medicating the patient. Before the pledget is applied 
the surface of the gum should be cleansed of the coat of mucus cover- 
ing it, otherwise the remedy will fail to come in contact with the mem- 
brane. It is equally important that dryness of the surface be secured. 
This application should be maintained for from twelve to fifteen seconds. 
If allowed to remain too long upon the part, vesication takes place. 
The general after-treatment consists in the repeated application of aco- 
nitum as above directed, the repetitions not being made at the same point 
more frequently than at intervals of forty-eight hours. When it is 
desired to increase the counter-irritation, the gum may be scarified very 
superficially by quick, light movements of a small scalpel. The patient 
should be instructed to avoid subjecting the tooth to extremes of tem- 
perature in either direction. The control period of conservatively 
treated cases is usually within the first fortnight after the capping. 

It is important that treatment be given at the beginning of the dis- 
turbance, when a few applications may suffice. Neglected cases, from 
the tendency to pulp disorders, are liable to pass beyond the curative 
stage. 

The interesting phenomenon is frequently observed that when the 
heat rate rises the pulp at first becomes more intolerant of cold. In 
case the pulp continues to respond to the remedy the range of tolera- 
tion should increase in both directions. 

Examples: No. 1, W. H. J., + 108°-73° ; 112°- 76°; +120° 
-74°; 124° -74°; 128° -67°; + 130° - 66°. No. 2, I. A. W., 
' + 120° - 84° ; + 120° - 86° ; 128° - 86° ; + 124°-76° ; + 134°-70° ; 
+ 140° -67°; +142° -66°; +142° -64°. 

It sometimes becomes necessary to open the cases and recap. This 
usually occurs when in reviewing the case it is considered that some 
oversight has befallen. There may have been two exposures. The 
cap may not have completely covered the exposed part. There may 
have been some compression from forcing the cap, or it may have been 
displaced during the after-procedures. 

Most careful records of all cases should be kept, with a relation of 
the condition and of the controlling symptoms. These records should 
be methodically preserved in a book kept for this purpose. Should sub- 
sequent irritation occur, a new diagnosis may be formed from the recorded 
facts and the new conditions. The record of conservatively treated pulps 
should be carried forward to the examination chart at each recurring 
periodic examination of the teeth. It is better that they be marked in 



CALCIFIC CHANGES IN THE PULP. 



417 



symbol with red ink, to prevent the unnecessary removal of temporary 
fillings and to explain the reason for their presence and thus avoid the 
accident of unnecessarily uncovering the pulp in such cases. 



Calcific Changes in the Pulp as related to the Operation 

of Pulp Capping. 

When loss of substance takes place slowly, either by carious action 
or by attrition, a notable calcific growth takes place in the pulp cham- 
ber opposite to the point of waste in the direction of the radiant course 

Fig. 394. 




Secondary dentin, resulting from irritation of the dentinal fibrils by caries (Black). A, Diagram 
of an incisor having a decay in the labial surface, a, and a deposit of secondary dentin at b. 
The point from which the illustration B is taken is shown by c. B, Illustration of the tissue 
of the secondary deposit in A : a, primary dentin ; b, secondary dentin ; c, seems to be a blood- 
vessel that has become calcified ; d, an irregular fault having some resemblance to the lacunae 
of bone ; e, pulp chamber. It will be noted that there are irregular deposits of granular matter 
in the substance of the secondary dentin, and that the tubules wind about them. 

of the tubules (see Fig. 394). If the loss of substance from the ex- 
terior progresses with sufficient slowness encroachment upon the pulp 
does not take place. The pulp chamber may become obliterated by the 
progressive deposition of calcific matter, which has the designation of 
secondary dentin. 

The morphological character of the secondary deposit is histologically 
irregular, being frequently of mixed character, presenting some of the 
characteristics of dentin and also containing cemental cells with radiant 
and anastomosing canal iculi. For this reason deposits have been 
designated as osteo-dentin. 

In the earlier years of life opportunity does not offer to study these 
changes of structure, as the usual progress of caries is too rapid, but in 
advanced life they are common, it being not infrequent to find complete 

27 



418 



CONSERVATIVE TREATMENT OF THE PULP. 



obliteration of the pulp cavity as well as of the canal of the root (see 
Fig. 395). In some instances nodules of calcific material appear un- 

Fig, 395. 





Calcification of the dental pulp (Black). At A is shown the outline of a lower molar with a cavity 
at b. The pulp chamber is much reduced in size and filled with calcific material, as shown in 
B. a, a large granular mass of calcific material, which is very transparent but finely granular. 
A very few irregular lines are seen in the centre, which slightly resemble dentinal tubes ; b, 
an erratic growth of irregularly formed and unusually transparent dentin ; c, line of the 
growth of dentin from the floor of the pulp chamber : the growth from other directions is so 
perfectly regular as to leave no markings ; d, margin of the cavity of decay ; e, a bundle of 
cylindrical forms of calcific material extending down into the root canal. These extended to 
the apex of the root. 

attached to the walls of the pulp cavity (Fig. 396). These increase 
sometimes by external development and in other cases by the coalescence 

Fig. 396. 

A 

r 




A, Outline of a lower molar, with a large carious cavity at a; b, pulp chamber. The shaded por- 
tion, c, was occupied by cylindrical calcifications. B, Illustration of the cylindrical calcifica- 
tions. X 100. (Black.) 

of several contiguous nodules. Again, several nodules inhabiting the 
pulp chamber may increase in size without becoming fused, and, accom- 



i 



CALCIFIC CHANGES IN THE PULP. 419 

modating themselves to each other as development progresses, they at 
length completely fill the cavity, from which they are severally removed 
with great difficulty. 

It is remarkable that while in some instances pulp nodules become 
the cause of producing violent pain by their pressure upon the nerves 
of the pulp, in the majority of cases substitution of the normal tissue 
takes place until nearly complete occlusion of the pulp cavity is affected 
without the occurrence of pain. 

Small pulp nodules are not infrequently found in pulps otherwise 
perfectly normal, but generally they are evidence of continued irritation 
of a mild form usually attending the progressive slow advancement of 
caries of the tooth. But this is not necessarily the case, since some of 
the most violent attacks of dental neuralgia have arisen from the pres- 
ence of nodules in perfectly sound teeth. 

The diagnosis of the existence of pulp nodules as the cause of pulp 
irritation is not easily made out. The determination of the condition 
usually can be reached only by the process of exclusion. As they do 
not occur early in life while the teeth are undergoing ordinary develop- 
ment, they may be looked for only after middle life. The pain is dull 
and reflected, and the paroxysms are frequent. There is sensibility to 
cold, and rarely pain appears on percussion. When the teeth are 
sound, the disturbing one will usually be determined by the tem- 
perature tests. 

An important differentiation from the usual irritation of ordinary 
pulp disturbance from exposure or the thermal irritation caused by the 
approximation to the pulp of large metal fillings, is that the disturbance 
from nodular irritation is not rapidly progressive and that the irritation 
may continue without marked exacerbations or subsidence for consider- 
able periods. 

Treatment is useless which does not include drilling to the pulp and 
devitalizing it. The difficulties involved in treatment by devitalization 
are liable to be attended by great pain, since when the pulp chamber is 
much occupied by nodules the action of the devitalizing agent has not 
free course. In these cases the remains of the pulp between the nodules 
and the walls of the chamber are attenuated, and when irritated by the 
arsenous acid give expression to an excessive degree of pain. 1 

The Influence of Pulp Exposure, and the Effect of Conservative Treat- 
ment of the Pulp upon Calcific Depositions. — Allusion has been made 
to calcific deposits occurring on the walls of the pulp chamber as the 
result of peripheral irritation. Here, as stated, these accretions only 
occur when the degree of irritation is slight and of long continuance. 
The examples of this which have been given in dental literature are 

1 For the form and extent of nodular calcification see American System of Dentistry. 



420 CONSERVATIVE TREATMENT OF THE PULP. 

conclusive as to the ability of the pulp at all stages of its existence to 
take on this action when the conditions are as stated. On the contrary, 
when the disturbances are active the formation of calcific deposits on 
the walls of the pulp chamber do not take place, or if in the earlier 
progress of decay they have commenced, as the progress of the destruc- 
tive action approaches the pulp this change is suspended, and in some 
instances resorption of the secondary deposit takes place. 

It is apparently in this manner that the pulp becomes denuded under 
the influence of thermal or traumatic irritation in cases in which there 
was no evidence of exposure at the time of the preparation and filling 
of the cavity. This result Avould appear to be related to the principle 
that secondary structures and tissue of repair are liable to resorption as 
the result of irritation or disturbances of nutrition. 

The frequent occurrence of secondary dentin following the conserva- 
tive treatment of the pulp and in some instances occurring spontaneously 
over exposed pulps, raises important considerations connected with the 
subject. The writer has had many instances come under his observation 
in which secondary dentin has obliterated exposures, both in his own 
cases and in those of others. 

The influence of the tendency to nodular deposits upon the results 
of conservative treatment does not appear to be detrimental unless the 
pulp chamber becomes largely filled with them. The pulp at the period 
of life when calcific deposits usually take place is not so sensitive as it 
is at an earlier age, and therefore, unless senile conditions appear to be 
present or imminent, the existence of such deposits should not be inim- 
ical to the preservation of the pulp. The writer, who has had frequent 
cases of pulp devitalization after conservative treatment, has rarely ob- 
served " pulp stones " in these cases. 

It is an important consideration that when calcific deposits take 
place beneath fillings where the pulp has been nearly exposed, or where 
they have followed conservative treatment of the pulp, they are liable 
to resorption on the occurrence of irritation of the pulp from any cause 
which brings on an increased blood supply. This is more remarkable 
since there are no lymphatic vessels in the pulp. This change can occur 
only by the development of osteoclasts on the surface of the pulp. 
Of this development there have been several recorded instances 
where the dentin has suffered resorption until the enamel has been 
encroached upon by the process of denudation, and when favorable 
conditions were established a deposition or formation of secondary 
dentin has occurred. 



DEVITALIZATION AND EXTIRPATION OF THE PULP. 421 

Devitalization and Extirpation of the Dental Pulp. 
When the existing conditions are such as to require the devitalization 
of the pulp there are several requirements essential to secure a satis- 
factory result : 

(1) That little pain be inflicted. 

(2) That the destruction be quickly effected. 

(3) That precaution be taken to prevent discoloration of the dentin. 
The first requirement is the most important, since, if the means used 

to effect the devitalization are painless or nearly so, the pulp promptly 
yields to the devitalizing agent and there is little danger of discoloration 
of the dentin. 

At present there are three general methods of procedure : by chemi- 
cal means, by extirpation with suitable instruments, and by narcotization 
of the tissue. 

Reliance has usually been placed upon chemical agents, these being 
— 1. Zinc chlorid ; 2. Caustic potassa ; 3. Chromic acid ; 4. Arsenous 
acid ; 5. Arsenical ore (cobalt). 

The agents 1, 2, 3 are usually painful, of slow progress, difficult of 
application, and uncertain. Hence arsenous acid has usually been 
depended on. This substance, notwithstanding certain objections, is the 
most available and most reliable of the substances above named. It 
has generally been combined with acetate of morphin in variable pro- 
portions, to which has been added in the formation of this paste a suf- 
ficient quantity of creosote, carbolic acid, or one of the essential oils, to 
give the combination the consistence of cream. 1 

In making this formula it is important that the ingredients be 
thoroughly ground together to effect the comminution of the arsenic 
and the morphin as well as to intimately mix the components. The 
morphin is used as a sedative to counteract the excessive irritation fre- 
quently caused by the action of the arsenous acid, which is also modified 
by the anesthetic influence of the creosote. Carbolic acid has been fre- 
quently substituted for creosote as being of less disagreeable odor, and 
as, from its coagulative action upon the surface of the pulp, it prepares 
the tissue to absorb the arsenic and markedly lessens the time of absorp- 
tion. It is a well-known fact that with great frequency the application 
of arsenous acid to the pulp is so greatly irritating to it that much pain 

1 Of late cocain has largely superseded the morphin salt as an ingredient of these pre- 
scriptions. As — 

R Acid, arsenosi, 

Cocainse hydrochl., da, pars seq. 

01. caryophylli, q. s. 

M. et ft. pasta. 



422 CONSERVATIVE TREATMENT OF THE PULP. 

is excited, which brings about congestion of the surface of the pulp to 
such a degree as to delay absorption of this agent. 

When the above-stated combination is applied to a living pulp which 
has not been in a state of disturbance, and therefore is in the condition 
of quiescence considered in the section on conservative treatment of the 
pulp, little or no excitement of the organ takes place. If the paste be 
carefully applied in such a manner as to avoid pressure the pulp does 
not usually become excited and promptly succumbs to the chemical force 
of the arsenic. When on the contrary the pulp is in a condition of 
active congestion, such as is presented by cases of prolonged exposure, 
and where congestion has supervened as the consequence of futile 
attempts at conservation, violent further excitement of the pulp is 
nearly certain. In this condition the pulp resists the absorption of the 
arsenic and repeated applications are likely to produce no better results. 
The failure to discriminate between the different conditions of the pulp 
accounts largely for the variation in the action of the same formula 
upon the exposed pulp. 

It becomes important, therefore, to reduce the state of hyperesthesia 
of the pulp and to relieve the congestion in many instances before 
commencing the devitalization. 

The relief of congestion requires, first, the disinfection of the surface 
of the pulp and of the dentin contiguous to it. The most efficient 
agent for this purpose, generally, is formalin, which after the first slight 
pain produced by it is almost immediately soothing. Formalin owes 
its value as a disinfectant to its extreme diffusibilityand in the strength 
applicable does not appear to be coagulative in its action. The strength 
should for this purpose not be greater than 2|- per cent. As formalin is 
composed of 40 volumes of formaldehyd with 60 of water, the above- 
stated percentage of formaldehyd is produced by adding 1 volume of 
formalin to 14 volumes of water. 

When violent congestion is manifest and when the pain attending 
the removal of the carious matter forbids the complete baring of the 
pulp, a paste composed of tannic acid and oil of cloves sealed in the 
cavity will so far subdue the conditions as to permit complete removal 
of the caries. This application should be allowed to remain for several 
days. This paste should be contained in a large concave cap and 
secured with one of the plastic cements. 

For the relief of ordinary congestion of the pulp cocain offers the 
best means, since it has direct and positive action over the capillaries, 
which has generally been adduced to account in part for its anesthetic 
influence, as by lessening the supply of blood in the capillaries it there- 
by reduces the stimulation of the nerve fibrils. In cases of known con- 
gestion as determined by the symptomatology when there is no effusion 



DEVITALIZATION AND EXTIRPATION OF THE PULP. 423 

of lymph or pus from the exposed surface, the pulp is bathed with a 
strong solution of cocain and is then covered with a deep cap filled with 
a paste of cocain and oil of cloves hermetically sealed in for several 
days, when usually the arsenical paste may be used with much-lessened 
danger of irritation. 

In these cases, and indeed in all cases, an excellent formula for de- 
vitalization will be found in the combination of 10 grams of arsenous 
acid ground well with 20 grams of cocain. This is taken upon a minute 
pledget of cotton previously charged with oil of cloves or carbolic acid, 
which is laid upon the exposed point and then sealed in hermetically, 
care being taken to avoid compression by arching over the dressing a 
suitable cap, or by flowing over the dressing a soft paste of one of the 
mineral cements. Too much care cannot be taken concerning the 
protection of the gum from escape of the arsenical preparation, since 
serious destruction of the gum and alveolus may be produced by the 
exuding of the arsenic. 

When there is evidence of the exudation of pus, this is checked by 
the application of deliquescent zinc chlorid or by washing with pyrozone. 
Usually in such cases the surface of the pulp has become necrotic by 
the suppurative process and will not be so repel lant of the arsenic as in 
ordinary cases. 

The time usually required for the action of the arsenic to reach well 
toward the apex of the roots is from four to six days. This, however, 
depends upon the quantity of the preparation applied and the resistance 
of the pulp tissue. As the aim should be to procure the nearly com- 
plete death of the pulp by one application, the longer period is preferable 
as entailing less difficulty and the expenditure of less time than when 
shorter intervals are allowed. 

When the application is made to an entirely quiescent pulp it will 
often be found that at the end of one or two days a broach may be 
passed to the end of single-rooted teeth, when the pulp may sometimes 
be removed. In these cases, if the pulp be not then extracted, it will 
be found in some instances that at a subsequent period the organ has 
apparently recovered its sensitivity. The explanation of this is that the 
arsenic apparently paralyzes the nerves of the pulp without having acted 
deeper than the surface. In this case the application should be repeated 
for a lengthened period without disturbing the tissue. On removing 
the dressings if the broach cannot be passed to the end of the canal 
either of two courses may be pursued ; the application may be repeated 
without removing the devitalized portion, or a strong solution of cocain 
may be carefully instillated until it is conveyed to the apex of the canal 
by means of a broach. This procedure is best effected by isolating the 
tooth with rubber dam and then filling the pulp chamber with the solu- 



424 CONSERVATIVE TREATMENT OF THE PULP. 

tion of cocain, which may be conveniently conveyed forward by gentle 
advancements and withdrawals of this instrument. The best form of 
instrument for this purpose is the Swiss broach tempered a little beyond 
a spring temper. 

A matter of considerable importance in connection with the instru- 
ments used in these manipulations is that they be either such as have 
not been previously used or that they be thoroughly disinfected previous 
to use. If an instrument of this kind is indiscriminately used, having 
probably been infected by some purulent case, septic disturbance of the 
tissues at the apex is brought about. The safest course is to use a new 
broach suited in size and stiffness to the case in hand. 

Since cataphoresis has been employed in dentistry it has been fre- 
quently used to effect the anesthetization of the pulp by cocain. This 
method has certain advantages. The time expended in the procedure 
is from ten to thirty minutes. The requirements are that insulation be 
perfectly secured ; that the selected voltage be low at the commence- 
ment — in most instances from 5 to 10 volts — and be gradually increased 
as the pain limit will permit. 

The impediments are the usual small size of the foramina and the 
density of the pulp walls. When the foramen is large the resistance is 
less and the action prompt. 

Cocain may be employed in this manner to obtund the parietes of the 
cavity and the surface of the pulp, when after the removal of the carious 
matter the pulp may be uncovered. The application can then be 
renewed to complete the anesthetization of the pulp. 

This procedure saves much time and discomfort and also avoids 
pain as compared with devitalization by chemical means. It is indi- 
cated in cases of severe congestion of the pulp, in which arsenic usually 
produces great pain and often is without satisfactory result. 

In some instances complete obtundation is not effected throughout 
the extent of the pulp. Here, after removal of the part anesthetized 
the remainder may be devitalized easily by " White's fiber," which is 
the safest arsenical preparation to use under these conditions. 

Instillation of cocain by means of a broach may also be efficacious. 

A further advantage in this method of treatment is that when the 
anesthesia is completed the pulp may be entirely removed and the 
canal be filled at the same sitting. 

It is sometimes observed, as the result of forcing the current beyond 
reasonable limits, that soreness of the peridental membrane follows. 
What effect has been produced in this instance is not clearly apparent. 
Whether it is a result of undue pressure of the current upon the apical 
tissues or is caused by the interference of cocain with the nutrition of 
the parts has not been determined. This effect is mentioned to induce 



PRECAUTIONS TO PREVENT DENTINAL DISCOLORATION. 425 

the degree of caution which is the accompaniment of an intelligent use 
of a force of signal service when carefully applied, but which recklessly 
pushed may do injury. 1 

The Pressure Method of Obtunding the Pulp. 

A method of applying cocain to the pulp under pressure has recently 
come into use. It consists of laying over the exposed surface, after 
the pulp is carefully and broadly uncovered, a small piece of amadou 
(punk) filled with a saturated solution of cocain in absolute alcohol or 
chloroform. The cavity is then filled with a piece of unvulcanized 
caoutchouc. Pressure is effected directly upon the rubber with a broad 
rounded instrument, so adapted in size that it will not meet with 
impediment and yet not small enough to exert force directly upon the 
point of exposure. The degree of pressure should at first be slight, and 
be gradually increased as the cocain exerts its effect upon the pulp. 
The force is exerted by successive steps, terminating when pain follows, 
but maintained until the sensation ceases. At length when no pain is 
produced by excessive pressure the rubber and punk are removed, when 
the pulp is immediately removed by the usual means. This operation 
is done quickly, to avoid the return of sensitivity. 

Those who pursue this plan state that it produces nearly uniform 
results and enables the canal and pulp chamber to be filled immediately. 

The indications are that the cocain overcomes the sensitivity of the 
surface of the pulp, and that pressure paralyzes the tissue by the com- 
pression to which it is subjected. Were the cocain conveyed to the 
apex, as when it is instillated, pain would not so soon return. 



Precautions required to Prevent Discoloration of the 

Dentin. 

It sometimes occurs where arsenous acid produces much irritation 
of the pulp that the violent congestion occasions disorganization of the 
blood corpuscles, resulting in the distribution of the hematin throughout 
the dentin. This most unfortunate result is liable to follow the applica- 
tion to an already congested pulp when the application is made without 
first subduing this condition. It is also more liable to happen when 
under these circumstances the pulp has not been completely denuded of 
the carious matter. 

The removal of the ultimate layers of carious matter is important to 
permit the pulp to bleed and thus to deplete the engorged vessels. It 
is also necessary to avoid making an arsenical application until the 

1 The student will find much instruction in Price's "Foundation Principles of Den- 
tal Cataphoresis," Items of Interest, vol. xx. p. 345 et seg. 



426 CONSERVATIVE TREATMENT OF THE PULP. 

assurance is reached that the bleeding has completely ceased, else subse- 
quent bleeding may induce discoloration. In addition the bleeding or 
any other kind of effusion prevents direct contact between the pulp and 
the arsenical paste. 

These general directions apply also to the employment of pow- 
dered cobalt as a devitalizer. The difference between the action of 
cobalt and arsenous acid is due to the variations in their respective 
solubility in the fluids of the pulp — cobalt having a low rate of solu- 
bility. For this reason this substance requires a longer interval, at 
least a week being necessary for its action to extend into the canals. In 
anterior teeth a shorter period should be chosen. With this substance 
it is of extreme importance that the application be made directly to the 
pulp. The method is as follows : 

A pellet of cotton the size of a pinhead is saturated with any of the 
essential oils ; it is then dipped in the powder and laid upon the pulp. 
The previously stated precautions are taken to prevent pressure of the 
pellet of cotton upon the pulp and to protect the cavity from the ingress 
of moisture. 

In these procedures connected with the removal of the pulp the use 
of alcohol is an important aid, since on account of its affinity for water 
it much aids, in addition to its cleansing properties, in the procurement 
of dryness of the parts. Desiccation of the pulp chamber materially 
assists in all the delicate procedures connected with the treatment of 
this class of cases. It lessens the pain of the remaining living portion 
of the pulp, and by giving firmness to the devitalized part makes more 
easy the removal of the dead tissue. It also facilitates the action of the 
disinfectants which may be employed to prevent rapid changes in the 
organic contents of the canal. The process of desiccation may be much 
facilitated by the concurrent injection of warmed air. 

It should be emphasized that in all procedures connected with 
the treatment of pulps undergoing devitalization the teeth should be 
isolated by the use of rubber dam. This is necessary not only to 
facilitate observation and secure dryness but to protect from mouth 
infection. 

The removal of the dead pulp tissue is effected by small barbed 
broaches which are passed between the pulp and the walls of the canal. 
When these reach the apex the pulp may in most instances be wound 
upon the instruments by a gentle rotation. When this does not take 
place because of the loss of consistence of the tissue, it is broken up by 
constant rotation of the instrument and removed piecemeal. The dis- 
placement of the shreds is best effected by wrapping the broach w T ith a 
few fibers of cotton dipped in alcohol. 

Previously to this, free communication must be established between 



PRECAUTIONS TO PREVENT DENTINAL DISCOLORATION. 427 

the cavity and the pulp chamber, as well as such a formation of the 
lines of approach to the canals of the root as will give free access, not 
only for the removal of the dead tissue, but as well to facilitate the 
complete closure of the root canals to the apices to prevent the ingress 
of organic matter from the adjacent tissues. 

Minute directions for the form of approach to the various canals and 
the related procedures will be found in the next chapter. 



CHAPTER XVII. 

THE TREATMENT AND FILLING OF ROOT CANALS. 

By Henry H. Burchard, M. D., D. D. S.. 



Pathological Conditions. 

The modes of treatment of the pulp chambers and canals of teeth 
containing non-vital pulps, or those in which the pulp is absent, are 
determined and governed by the pathological conditions present. These 
conditions may be broadly divided into aseptic and septic ; i. e. those 
which have not been invaded by micro-organisms, the others those in 
which the pulp or its remnants furnish the soil in which the develop- 
ment of micro-organisms has taken place. 

The first class includes those cases in which the pulp has been inten- 
tionally devitalized en masse, and also those in which the organ has 
undergone a process known as mummification, or dry gangrene. This 
latter condition is occasionally found as a consequence of traumatic 
death of the pulp without exposure, and sometimes as a sequel of 
attempts at conservation of exposed pulps by capping them with zinc 
oxychlorid. 

The septic cases may be divided into classes according to the depth 
of invasion of septic organisms ; they range from superficial ulceration 
of the pulp, to its disorganization through the agency of putrefaction, 
and the infection of the tissues beyond the apex of the root. 

Immediately upon or even before exposure of the dental pulp, 
its surface, and subsequently its substance, is invaded by several 
of the many forms of organisms which find a habitat in the human 
mouth. 

The first of the septic cases are those in which organisms have 
invaded the coronal portion of the pulp and destroyed part of its sub- 
stance — through a process of ulceration. Such cases become aseptic 
through the removal of the pulp en masse, provided no organisms be 
carried into the canal during or subsequent to the removal of the 
pulp. 

The second class of cases comprises those in which septic organisms 
have invaded the pulp along the direction of its veins and destroyed 
the mass of the organ through a process of suppuration. In these cases 

429 



430 



THE TREATMENT AND FILLING OF ROOT CANALS. 



it is not uncommon to find the tissues of the apical region affected in 
some degree presumably by infection with the waste products of the 
organisms, a transitory pericementitis occurring which ceases when the 
dead pulp sloughs from its vital connection at the apex. The succeed- 
ing stages of the infection are those of moist gangrene and putrefactive 
decomposition of the pulp tissues, and later of the contents of the 
tubules. Following upon these conditions are affections of the cemen- 
tum and the pericementum in the apical region, resulting in an inflam- 
matory process in these parts. 

All of these stages of infection and decomposition may be found in 
the pulp at one time, the suppurative process preceding that of putre- 
faction. Cultures made from a gangrenous pulp (see Fig. 397) 1 showed 



Fig. 397. 






c 



.;•/ 






4 5 

Micro-organisms found in cultures from a gangrenous pulp. 

the smaller cocci and diplococci (5) nearest the apex of the root (c, Fig. 
397, 1) where suppuration was in progress ; the larger forms and more 
varieties were found in the necrosed and decomposing portions of the 

1 Miller, Dental Cosmos, July, 1894. 



PATHOLOGICAL CONDITIONS. 431 

pulp (4, 3, 2). The cases of gangrenous pulps exhibit a mixed infec- 
tion, several varieties of cocci, bacilli, and spirochetes being found. 1 

Cases are occasionally seen in which the pulp of a non-carious tooth 
has been devitalized in consequence of a blow, injuring the vessels as 
they enter the apex of the root ; the same effect is not rare as a conse- 
quence of too rapid or extensive movement of teeth in regulating. The 
pulps in such cases are probably destroyed by thrombosis of the vessels 
at the root apex. The death of the pulp may not be detected for years ; 
when evidences of albuminous decomposition are discovered, a growing 
opacity and changing color of the tooth may be detected. In other 
cases alveolar abscesses may form and discharge at some point near the 
tooth, or it may be at some distance from it. It is presumed that the 
organisms which have effected this decomposition of the pulp resulting 
in the suppurative process have found their way to it via the blood 
current. 

It is within the experience of every dentist that the products of 
decomposition occurring under these conditions afford a suitable soil for 
the development of virulent micro-organisms as soon as the tooth is 
opened to the air. 

The several conditions described are to be regarded, for purposes of 
treatment, as definite pathological states. The treatment is to be 
directed to the attaining of such conditions as shall insure the retention 
of the tooth with an entire absence of pathological manifestations. 
Rational therapeutics should govern each procedure. 

Cases in which the Pulp has been Intentionally Destroyed and Re- 
moved en masse. — As this procedure usually has been determined upon 
in consequence of suppuration or inflammation of the pulp, the septic 
organisms, the staphylococci, streptococci, and bacilli, have followed 
the course of the inflammation, i. e. along the veins. The organisms of 
putrefaction, if present, have affected but in very limited degree the 
most external portions of the pulp, so that the color of the dentin is 
unaltered except to a very slight depth. After the removal of the pulp 
the contents of the tubules are chemically unchanged, and the canals 
contain no organic matter, except the blood which may have escaped in 
consequence of tearing away the pulp. There may also remain odonto- 
blasts which have become mechanically detached during the operation. 
Provided no organisms have been introduced during or subsequent to 
the operation of extirpation, the canals are aseptic. If proper anti- 
septic precautions have been taken, sterilizing and isolating the tooth to 
be operated on and also the instruments employed, no infection occurs. 
These are the cases in which immediate root filling has been recom- 
mended and practised with success. 

1 See Fig. 397. 



432 



THE TREATMENT AND FILLING OF ROOT CANALS. 



Fig. 398. 
Pigment. S + hemoglobin 



C0 2 ,NH 3 ; 
HoO and H 2 S 



fatty 
ucts. 



If the septic process has invaded the pulp extensively the pulp 

tissue, as its destruction progresses, be- 
comes the seat and soil of putrefactive 
decomposition involving also to a vari- 
able extent the contents of the dentinal 
tubules, and the color of the dentin un- 
dergoes a series of changes. 1 The ap- 
pended figure (Fig. 398) gives a graphic 
diagrammatic representation of the serial 
decomposition of an infected pulp. The 
albuminous constituents of the pulp un- 
dergo fatty transformation ; next putre- 
factive decomposition attended by the 
evolution of hydrogen sulfid, ammonia, 
and other end products. According to the 
Aromatic and extent of invasion and its variety, waste 
prod- products are formed (ptomains and al- 
lied substances) by the organisms which 
act as irritants to the vital tissues, until, 
when the apical but still vital portions 
of the pulp become the soil for the de- 
velopment of pyogenic organisms, the 
tissues of the apical region are affected. 
Usually in the later stages of pulp sup- 
puration the tooth becomes sensitive upon percussion. Succeeding this 
state of affairs is a period of delusive quiet, during which the apical 
tissues, although doubtless affected by the toxic substances present, 
exhibit but slight subjective symptoms. The remnants of the pulp are 
undergoing progressive decomposition, as are also the contents of the 
dentinal tubules. After a variable period, governed by the virulence 
of the organisms present and the inherent resistance of the vital tissues 
of the apical region, these latter succumb, poisoned by the toxic sub- 
stances formed in contact with them, and an inflammatory action arises ; 
this may be subacute, evidenced by sensitiveness upon percussion and a 
deepening of the gum color overlying the apex of the root, constituting 
a condition known as subacute pericementitis ; or, if the attack be more 
severe, or the resistance lessened, the symptoms are more violent ; there 
is a pronounced hyperemia, quickly succeeded by the evidences of 
marked inflammatory action. The tooth, owing to the effusions in the 
pericementum, becomes elevated and exquisitely sensitive to touch ; 
the color of the gum deepens, and heavy throbbing pain is complained 
of; acute pericementitis is in progress. In more severe cases marked 
1 See Chapter XX. on Bleaching. 




Ptomains. 



Peptones, 
Pus. 



THERAPEUTIC AGENTS. % 433 

oedema of the gum and it may be of the face arises ; the pulse increases 
in volume, tension and frequency ; febrile action, with a temperature as 
high as 103° or 104° may occur; in other cases distinct evidences of 
septic intoxication may appear, and indeed even septicemia or pyemia * 
may result at a later stage. 

The severity of the inflammatory action is no doubt governed in part 
by the variety of the infecting organisms, and again by the physical 
condition of the individual attacked. Judging from the mode of prog- 
ress and attack, the staphylococci are the offenders where the inflam- 
matory action is circumscribed, and the streptococci in cases which 
exhibit a tendency to spread along the course of the fascia and produce 
phlegmonous inflammation. 2 Schreier has found the almost invariable 
presence of a diplococcus in this condition, probably the diplococcus 
pneumonice. 

Individuals presenting any of the several manifestations of struma, 
inherited or acquired, suffer from a debility of general vital processes, 
and may have the inflammatory action run a riotous course (see 
Alveolar Abscess, Chapter XVIII.). As a rule, when a tooth has been 
the seat of subacute pericementitis for a lengthened period, or of acute 
septic pericementitis for from twenty-four to forty-eight hours, there is 
more or less death of cellular elements in the inflammatory effusion,, 
pus forms, and alveolar abscess is established (see Chapter XVIII.). 

In cases of subacute pericementitis, even those in which pus forma- 
tion is not evident, the tissues of the apical region are assailed by the 
products of putrefactive decomposition, which latter process may prove 
difficult to overcome, the tissues rebelling at each attempt to close the 
outlet to the escape of gases which irritate them. 

Each phenomenon mentioned as accompanying the stages of septic 
infection and albuminous decomposition forms an item for consideration 
in the therapeutic measures to be applied. 

Therapeutic Agents. 

The natural and true inference from what has been stated is that the 
class of therapeutic agents to be locally employed in any of these condi- 
tions are all included under the general order of germicides, antiseptics, 
and disinfectants. 

The one distinguishing feature that all of these substances have in 
common is the power — differing in degree in each — of destroying patho- 
genic organisms or rendering innocuous their waste products ; their 
other properties differ widely, so that the agent for application to spe- 

1 See case of Dr. E. T. Darby, Proc. Odontological Society of Pennsylvania, 1892. 

2 See case reported by Dr. E. C. Kirk, Proc. Odontological Society of Pennsylvania, 
1892. 

28 



434 THE TREATMENT AND FILLING OF BOOT CANALS. 

cific disease conditions is selected with a regard to which shall best and 
most completely attain a definite end. According to the effects produced 
upon albumin the agents under consideration may be placed in two 
classes, coagulants and non-coagulants. In the former class are in- 
cluded salts of the metals and alcohols ; in the latter, many of the 
essential oils. 

Mineral acids and the alkalies act by chemically destroying the 
albumin. The metallic salts which have been employed or tested as 
germicides in pulp canals are the chlorids of zinc and of aluminum, the 
bichlorid of mercury, the bichlorid of gold and sodium, the sulfate of 
copper, and the nitrate of silver. The salts of copper, silver, and gold 
are not adapted on account of the discolorations produced by them. 
Mercuric chlorid is open to the same objection ; thus the only metallic 
salt having general application is zinc chlorid. 

The alcohols employed are the ethylic (commercial) alcohol ; phenylic 
alcohol, i. e. carbolic acid, and creosote, with the coal-tar derivatives, 
the cresols. In this connection formalin — a 40 per cent, solution of the 
gas formaldehyd in water should be mentioned very favorably ; in 
dental practice it is reduced to a strength of 3 to 5 per cent. 

Preparations of iodin, bromin, and chlorin are all powerful anti- 
septics and disinfectants. Bromin is inapplicable owing to its irritat- 
ing effects and offensive odor ; chlorin is employed in the form of 
hypochlorites ; usually in the solutions called electrozone and meditrina, 
electrolytic products of sea-water. Labarraque's solution of sodium 
hypochlorite appears to have fallen into general disuse, as have also the 
hyposulfites. The usual form in which iodin is applied is as the 
tincture. Iodin trichlorid is said 1 to be five times as strong as mercuric 
chlorid as an antiseptic. 

The essential oils recommended as antiseptics for employment in 
canal and dentin sterilization are those of thyme, cinnamon, cassia, 
myrtle, and eucalyptus. 

The alkalies employed as sterilizing agents are Schreier's alloy of po- 
tassium and sodium, called Kalium-natrium ; sodium carbonate and so- 
dium dioxid. The mineral acids which have been recommended are hydro- 
chloric and sulfuric, the latter by the method described by Dr. Callahan. 2 

The gases oxygen and chlorin, in statu nascendi, are employed as 
sterilizing agents, the former extensively. When these are applied as 
bleaching agents, the sterilization is coincidently accomplished, as 
pointed out in the chapter on Bleaching. 

Oxygen is liberated from aqueous and ethereal solutions of hydrogen 
dioxid and solutions of sodium dioxid. 

1 Langenbach, quoted by Miller, Dental Cosmos, vol. xxxiii. p. 342. 

2 Proc. Ohio State Dental Society, 1894. 



THERAPEUTIC AGENTS. 435 

Iodol, iodoform, and kindred substances are not employed as germi- 
cides per. se, but for other therapeutic properties possessed by them, e. g. 
their supposed capability of maintaining sterilization after the more 
powerful antiseptics have been employed as germicides. 

Aristol, dithymol binioclid, is another member of this group, which 
owing to its chemical composition is theoretically preferable to the 
others. It contains twice the quantity of iodin in loose combination, 
and in addition has as its base a powerful antiseptic, thymol. 

These agents are supposed to act as antiseptics in consequence 
of setting free iodin when brought in contact with albuminous 
substances. 

It has been demonstrated that iodoform is not a germicide (organ- 
isms growing about it), but it appears to lessen or destroy the effects 
of toxic substances generated about it as the result of albuminous de- 
composition. 

The final antiseptic to be mentioned is the mechanical removal of 
infected tissues. 

Zinc chlorid forms, when brought in contact with albumin, a dense 
and almost colorless coagulum of zinc albuminate. Placed at one end 
of a capillary tube containing albumin, it diffuses rapidly through the 
solution, coagulating it throughout. l 

Carbolic acid forms less dense coagula, and creosote still less. 
Mercuric chlorid and silver nitrate form complete coagula also. It may 
be AA r ell in this connection to call attention to an observation made by 
Dr. Kirk, in an essay read before the First District Dental Society of 
New York, that coagulation is a chemical process, as illustrated in the 
union of mercuric chlorid with albumin. The metallic salt does not 
act by catalysis, but there is a distinct quantitative relation between the 
coagulant and the coagulable material, the process ceasing when the 
quantitative relation of these bodies is chemically satisfied ; if an excess of 
HgCl 2 be employed, a definite amount of the salt combines with albumin 
to form an albuminate of mercury suspended in a solution of the chemical 
excess of HgCl 2 . If an excess of the albumin be employed, an albumin- 
ate of mercury is formed suspended in a solution of albumin. The albu- 
minate of mercury when brought in contact with an easily decomposable 
sulfur compound may be reduced by the formation of mercury sulfid 
and the albumin be restored to its primary condition, 2 which would 
seem to indicate that HgCl 2 is an unreliable germicide where putrefac- 
tive decomposition is in progress giving rise to H 2 S. 

Formalin readily and quickly affects both albumin and gelatin, con- 
verting them into a tough coagulum which maintains its form and 

1 Prof. James Truman, Proc. Academy of Stomatology of Philadelphia, Dec. 1894. 
2 Abbott, Principles of Bacteriology, 3d ed., 1896. 



436 THE TREATMENT AND FILLING OF BOOT CANALS. 

appears to be persistently antiseptic for certain varieties of micro- 
organisms. 

The essential oils act as antiseptics without coagulation, having 
markedly less germicidal action than the agents above mentioned. 
Placed in root canals they diffuse through the dentin, maintaining a 
prolonged antiseptic influence ; their absorption into the dentin pro- 
duces some degree of discoloration in that tissue. These oils differ in 
antiseptic power. Oil of thyme and oil of cinnamon stand at the head 
of the list, oil of cloves and eucalyptus being far below them in the 
antiseptic scale. 

The alkalies employed as antiseptics saponify the fatty matters formed 
in the course of albuminous decomposition, and dissolve albuminous 
substances with which they are brought in contact. The first of these, 
the alloy of potassium and sodium, when placed in contact with decom- 
posing pulp tissue, abstracts the elements of water from it, and sodium 
and potassium hydroxids are formed, which have the power of saponi- 
fying fats and dissolving albumins. Sodium carbonate has similar 
properties, but acts less energetically. Sodium dioxid under the same 
conditions forms sodium hydroxid, nascent oxygen being set free, which 
acts as a germicide and also decomposes the coloring substances in the 
dentinal tubules, acting as a bleaching agent to the dentin. Solutions 
of hydrogen dioxid are decomposed into water and nascent oxygen in 
contact with the putrescent canal contents ; the liberated oxygen acting 
as an oxidizer. 

The mineral acids when employed subserve a double office. Sul- 
furic acid placed at the mouth of fine canals unites with and decom- 
poses the calcium salts of the dentin, forming calcium sulfate, easily 
removable with the fine canal scrapers ; its second office is that of an 
effective germicide, destroying all organisms with which it is brought 
in contact. 

Materials for Filling the Root Canal. 

The materials employed to hermetically seal the apical foramina of 
sterilized canals are in the condition of solids inserted en masse or in 
successive portions ; or they are pastes applied alone, or upon some 
medium which acts as a vehicle. Another class are ordinarily solid, but 
are brought to a condition of fluidity before inserting them. 

The properties which should be possessed by a satisfactory canal filling 
are as follows : Impermeability — it should hermetically seal the apical 
foramen, effectually preventing the egress of pathogenic organisms or 
their waste products from the canals to the tissues of the apical region 
and vice versa, and.it should prevent transudations from the apical 
tissues into the pulp canals. It should be unchanged by the influences 



MATERIALS FOR FILLING THE ROOT CANAL. 437 

about it ; be un irritating to the soft tissues ; and possess sufficient 
plasticity to permit of its ready adaptation to the walls of the space it is 
designed to fill. It should be at least aseptic when applied, and pref- 
erably antiseptic : it is to be esteemed in the degree that it maintains 
this latter quality in combination with the other desiderata stated. 

The solid materials which have been employed for this purpose are 
gold foil, shredded tin foil, gold, copper and lead points ; wood points 
dipped in creosote have been used for this purpose. The readily oxi- 
dizable metals have not found favor owing to the possibility of dentinal 
staining following their employment. The plastic materials employed 
are softened gutta-percha cones and the zinc oxychlorid cement. The 
latter and also other pastes are frequently employed to fill the meshes 
of a wisp of crude cotton wool or asbestos fiber, these latter being the 
vehicle for carrying the paste into position. It is to be remembered 
that when cotton fiber is kept in prolonged contact with zinc chlorid, 
the cellulose undergoes a chemical change : it is converted into a pectous 
substance called amyloid, which is a colorless colloid, unchangeable in 
the conditions existing at the apex of a pulp canal. 

Cotton itself may be included among the plastic root fillings. 

The fluid substances employed are solutions of red gutta-percha 
base plate in chloroform, the solution called chloro-percha, which con- 
tains in this case vermilion ; if made of white gutta-percha it contains 
zinc oxid and a variable amount of other mineral substances. The 
other members of this class are salol and paraffin, made fluid by heat 
before insertion and becoming hard when cool. 

Gold was the first material adopted for the purpose of canal filling, 
being introduced in this connection by Dr. Maynard over fifty years 
ago. Properly adapted it may be made to hermetically seal the apical 
foramen. It is difficult to manipulate, and its removal after the type of 
adaptation required is wellnigh impossible. Tin has the same virtues 
and is open to the same objection, which in fact obtains when any metal 
is forcibly driven into the apical portion of the canal. It is held, how- 
ever, and with a measure of good reason, by those who advocate the 
employment of metal for this purpose, that when a pulp canal has been 
thoroughly sterilized and filled, the necessity for the removal of the root 
filling will never arise. The degree of confidence expressed in this opinion 
has not yet seryed to override the caution of the conservative operator, 
so that metals have an extremely limited employment in this connection. 

The plastic materials most frequently recommended and which sta- 
tistics and general experience demonstrate to serve most acceptably as 
canal fillings, are the oxychlorid of zinc and gutta-percha. 

The zinc cement when in paste form may be readily adapted to any 
accessible canals, and it maintains during and for some time after set- 



438 THE TREATMENT AND FILLING OF ROOT CANALS. 

ting an antiseptic action. The peculiar and specific influence exerted 
by this material upon the albuminous constituents of the tooth may be 
seen as a not infrequent sequel to its employment as a pulp capping. 
Many of such teeth whose pulp chambers have been opened some years 
after the capping operation are found to have had their pulps changed 
to a dry tough mass which has not been the seat of septic invasion ; 
moreover, the normal color of the dentin of such teeth has been main- 
tained, showing that no extensive chemical decomposition has occurred 
in the contents of the tubules. As a canal filling it becomes very hard, 
remains white, and when freshly mixed is markedly irritating to vital 
tissue with which it is brought in contact. Its removal when indicated 
may be accomplished by repeated applications of sulfuric acid after the 
Callahan method of opening canals. 

When the meshes of cotton are filled with the paste made thin, the 
zinc chlorid acts upon the cotton, converting it into amyloid ; so that 
if a pellet of cotton moistened with a sedative antiseptic be placed in 
the apical portion of a root canal and the thin paste placed over it, the 
filling of the apex after the chemical action noted consists of the un- 
changeable impervious amyloid and not of cotton. 

Long thin gutta-percha cones are readily made plastic, but the 
adaptation of the material to the walls of the canal is less intimate than 
is that of the oxychlorid of zinc. It is unchangeable in the conditions 
under which it is placed, and is the most bland and unirritating of 
filling materials. Its removal after proper placement is difficult but by 
no means impossible. The gutta-percha compound known as temporary 
stopping has similar properties, but is less tough in texture. 

The last of the plasties introduced is a resinous substance called the 
balsamo del deserto. It is probably an exudation from one of the 
varieties of pine or fir, Its virtues and employment were first described 
by Dr. W. H. White of Silver City, N. M. His experiments indicate 
that the resin has a pronounced antiseptic action ; it adheres to wet 
surfaces, and is perfectly non-irritating to soft tissues with which it is 
brought in contact. It remains unchanged when employed as a canal 
dressing. He finds that the roots of temporary teeth which have been 
filled with the material suffer no interference with the resorption process 
because of its presence. 

Thin solutions of gutta-percha in chloroform (chloro-percha) have 
wide employment as fillings for fine and tortuous root canals. These 
solutions may be carried into any canal which will admit the finest 
broach. They shrink in hardening, so that a canal filling of such a 
solution does not hermetically seal the cavity when the material is 
hardened. 

The solution is usually employed in combination with the gutta- 



MUMMIFICATION OF THE PULP. 439 

percha cones. Dr. R. Ottolengui L recommends a method which may 
be followed with advantage : A number of pieces of floss silk about an 
inch long are saturated with chloro-percha and dried ; these are then 
thrust in a chloro-percha canal filling while it is fluid. Should it ever 
become necessary to remove the filling, the projecting end of one of the 
pieces of silk is caught, and the entire filling may be withdrawn. 

The use of salol in this connection was first described and advocated 
bv Dr. Mascort of Paris. 2 Salol, the salicylate of pheuol, is mildly 
antiseptic. When brought into contact with alkalies it is decomposed 
into carbolic and salicylic acids, two powerful antiseptics. It melts at 
40°C. (104°F.), and if fused at or but little above this heat it crys- 
tallizes in a few minutes ; if the heat be raised to a higher point crystal- 
lization is delayed for some time after the mass has cooled far below its 
normal melting-point. The melted salol may be readily carried into any 
canal which will admit the finest broach. Portions of the material which 
mav be carried beyond the apical foramen appear to be unirritating. 

Reports as to the permanence and value of this material vary from 
enthusiastic endorsement to unqualified condemnation. Many of those 
who have used salol have found, upon reopening canals which have 
been filled with it, an absence of the salol ; however, where the practice 
has been to employ a central canal filling of gutta-percha, a cone of 
which material is thrust into the melted salol, in such cases its absence 
has not been observed. Salol has been found to suffer rapid decomposi- 
tion in canals which have been treated with one of the fixed alkalies 
just before the salol was inserted. 

Paraffin has been employed for a caual filling, made fluid by heat and 
carried into the canals ; it is bland, unirritating, unchangeable, and easily 
removable. 3 It may be used, mixed with aristol, in sterilized canals. 4 

Before discussing the cleansing of pulp canals, certain means and 
methods suggested for avoiding the necessity for the toil and care 
necessary to mechanically cleanse the more inaccessible canals require 
consideration. These agents are preservative pastes. 

Mummification of the Pulp. — As early as the introduction of 
arsenous oxid as a devitalizing agent it was noted that a certain per- 
centage — or rather, an uncertain percentage — of cases gave evidence of 
little or no disease after the application of arsenic and its sealing in a 
cavity by a filling. Later, it was found that applications of powerful 
antiseptics to exposed pulps not infrequently were followed by a long- 
continued quiet of that organ ; still later, when more definite knowledge 
was possessed of the pathological results which might follow the leaving 
of portions of pulp substance in the canals of teeth after devitalization 

1 Methods of Filling Teeth. 2 Dental Cosmos, 1894, p. 352. 

3 Ibid. i Ibid., June 1897. 



440 THE TREATMENT AND FILLING OF ROOT CANALS. 

by arsenic, it was observed that after saturating the canals with creosote 
or zinc chlorid solutions, many cases gave little or no evidence of peri- 
cemental disturbance thereafter. 

While it is unquestionably preferable to always thoroughly remove 
the last vestige of devitalized pulps, the time, care, skill, and expense 
involved in perfect cleansing are detriments to its universal practice. 
The only other possible solution of the difficulty is to so alter the tissue 
not removed that it shall remain permanently aseptic, and, if possible 
to make it so, antiseptic. 

Observations derived from clinical experience, although undoubtedly 
of great and permanent value, are indeterminate, and our truly scientific 
knowledge of this matter dates from Dr. W. D. Miller's experiments. 1 
He credits Dr. Witzel with the first systematic observations in this 
direction. Dr. Witzel in 1874, " devitalized the crown portion of pulps 
by means of arsenic, extirpated that portion leaving the pulp in the 
canals undisturbed, their exposed ends being treated as freshly exposed 
pulps." This is the method followed by Herbst, who employs cobalt 
(which is native arsenic sulfid or metallic arsenic) instead of arsenic 
trioxid. 

Dr. Miller's experiments have shown that none but the most power- 
ful and penetrating antiseptics have value as permanent sterilizers. 
These are : The cyanid, bichlorid, and salicylate of mercury, sulfate 
of copper, and oil of cinnamon. Orthocresol, carbolic acid, trichlor- 
phenol, and zinc chlorid penetrate the pulp tissue rapidly, but are too 
diffusible, disappearing in a few weeks. 

He classifies salicylic acid, eugenol, campho-phenique, hydronaphthol, 
a- and /3-naphthol, acetico-tartrate of aluminum, and some essential oils, 
resorcin, thallin, sulpho-carbolate of zinc, etc., as being of doubtful 
value. 

Those nearly or quite worthless are iodoform, basic anilin coloring 
matters, borax, boric acid, dermatol, europhen, calcium chlorid, hydro- 
gen dioxid, sozoiodol salts, tincture of iodin, spirit of camphor, and 
naphthalin. 

The preparation giving the best results consisted of — Mercuric chlo- 
rid, 0.0075 gram ; thymol, 0.0075 gram, in tablet form. 

The pulp is devitalized ; the crown portion and all the root portion 
readily accessible is removed ; one of the tablets is placed in the pulp 
chamber, crushed by means of an amalgam plugger, and covered with 
gold foil. The mercury salt tends to discolor the crown of the tooth, 
so that its employment should be restricted to the posterior teeth ; 
indeed, the necessity for its use would be, as a rule, found with these 
teeth, being those from which it is most difficult to extract pulp rem- 

1 Proc. Columbian Dental Congress, 1893. 



MUMMIFICATION OF THE PULP. 



441 



nants. Dr. Miller expresses faith in the power of oil of cinnamon to 
permanently sterilize pulp fragments. He suggests the experimental 
application of the sterilizing tablets to such teeth as are readily sal- 
vable yet which are for various reasons " consigned to the forceps." 
Dr. Theodore Soderberg of Sydney, IS". S. W., reports excellent 
results from a continuous practice of this variety of pulp sterilization. 
He employs a paste composed of— 



]^. Alum exsic, 
Thymol, 
Glycerol, 
Zinc oxid, 



da. 3j ; 
q. s. to make stiff paste. — M. 



It will be noted that he substitutes dried alum for tannin, originally 
used by him as the hardening agent : his experiments showed the 
tannin to be productive of discoloration. Mercuric chlorid is set aside 
for the same reason. Oil of cassia employed in the paste also caused 
discoloration. At present Dr. Soderberg adds a small quantity of 
cocain to the paste to prevent the pain arising from the action of the 
dried alum. He states (Nov. 1895) that he has in a year applied the 
paste in 97 cases and has had no untoward results. The method of 
placing the material is shown in Figs. 399, 400. 



Fig. 399. 



Fig. 400. 





a, Caries exposing a horn of the pulp. 



a, Root portion of pulp; b, mummifying paste 
c, zinc phosphate ; d, gold or amalgam. 



C. A. Firth of Queenleyan, N. S. W., 1 advises the omission of 
zinc oxid from the paste, to avoid the formation of the brown tannate 
of zinc. He suggests the use of a mixture of tannic acid and thymol 
equal parts, made into a paste with glycerol and applied with ivory 
instruments, to avoid discolorations. He expresses himself as gratified 
at the results obtained. Another formula suggested by the same gentle- 
man is — 

1 Dental Cosmos, May, 1896. 



442 THE TREATMENT AND FILLING OF ROOT CANALS. 



DESCRIPTION OF FIGS. 401, 402, AND 403. 1 

Fig. 401. — Fig. 3 gives in contrast a sectional view of deciduous and permanent upper teeth 
divided through their lateral diameters. 

Fig. 4, a sectional view of the corresponding lower teeth divided through their antero-posterior 
diameters, a, b, c represent, respectively, the deciduous and permanent front incisors in con- 
trast: d, e,f, the lateral incisors; g, h, i, the canines; k, deciduous molars, upper and lower; and 
I, m, the successors to the deciduous molars, the bicuspids ; n, o represent permanent molars. 
c,f, i, m, o have dotted lines indicating the thickness of enamel removed by wear, atrophy of the 
cementum, and reduction in the size of the pulp due to progressive calcification, these changes 
being incident to old age. 

Fig. 402 represents in Fig. 1, letters a to h and a toh, the longitudinal or vertical sections of 
the sixteen upper teeth, showing the labio-palatal diameter of the pulp chamber and canal in 
crown and roots, the section of the molars being through the anterior buccal and palatal roots, 
while the bicuspids d e and d_e illustrate the result of such a compression of the root as to 
divide the pulp chamber into two canals— a condition which so frequently exists in these flattened 
roots. The double-lettered series, d d to h h and d d to hh, represent in the molars a section 
through the posterior buccal and the palatal roots, from which is quite readily recognized the 
slightly greater lateral diameter of the pulp chamber in the crown and the larger canal in the poste- 
rior buccal root over that in the anterior buccal root, while the bicuspids lettered eedd and ddee 
illustrate a modified pulp chamber and canal, with bifurcation of the root in one, these being cut 
through a different axis or plane from the single-lettered series. 

Fig. 2, letters a to h and a to h, represent the sixteen lower teeth with the section through 
their long diameters, as in the upper series. These incisors illustrate the compressed or flat- 
tened condition of their roots in contrast with the cylindrical character of the roots of the upper 
incisors, while the bicuspids d e and d_e illustrate the singleness of their pulp chamber and the 
cylindrical condition of their roots as in contrast with the flattened or compressed condition of 
the roots of the upper bicuspids. The molars /, g, h and f, g, h represent sections through the 
anterior root, illustrating its compressed condition and divided pulp chamber in the first and 
second molar, and a somewhat flattened one in the anterior root of the third molar ; ff,g g ,hh 
and //, g g, h h represent the single and cylindrical pulp chamber in the posterior root of the 
lower molars, while bb, cc and aa,bb represent the incisors and canines of the same series, with 
modified pulp chambers arising from modified development. 

Fig. 403.— Fig. 1, from o to h and_a to_A, represents the upper teeth, with transverse or horizon- 
tal section through the base of the pulp chamber in the crown, viewing the entrance to the canals 
of the several roots, while the same letters in Fig. 2 represent the lower series in the same 
manner. 

Fig. 3 represents the upper teeth, with the transverse or horizontal section made below the 
largest diameter of the pulp chamber and through the canals after they have diverged from the 
central chamber, but before the roots into which they run have in the molars bifurcated. 

Fig. 4 in like manner represents the lower series, well illustrating the flattened or compressed 
condition of the canal in anterior roots of the molars and the division of the chamber, as is fre- 
quently found in the roots of the lower incisors. 

The letters aa,bb,cc,d d,ff, d_d and_ee (Fig. 3) represent the relative shapes, whether circu- 
lar, oval, or flattened, of the pulp canal in the roots of the upper central and lateral incisors, 
the canines, the first and second bicuspids, and the first, second, and third molars, while the 
same letters in Fig. 4 represent the relative shapes of the pulp canal in similar teeth in the 
lower series. 

1 These figures are taken from v. Carabelli's Anatomie des Mundes. 



Fig. 401. 

(For description, see page 442. 

05* 












^ff^.. 





443 



Fig. 402. 
(For description, see page 442.) 




444 



Fig. 403. 
(For description, see page 442.) 



ik 




«/ CO 



^b 



^ 



M 




// 



./? 





r 




fcX) 




/> 






^P 



6 



*L 



*/i 



% 





/ 




V ? 









fcb 






445 



446 



THE TREATMENT AND FILLING OF ROOT CANALS. 



1^. Mercuric chlorid, 
Thymol, 
Acid, carbolic, 
Acid, tannic, 
Morph. mur., 
01. menth., 
Ol. cassise, 



da. 2.0 grams ; 

ad. 1.5 gram ; 

da. q. s. to make stiff paste. — M. 



" A tannate of mercury is formed ; it is insoluble, and but little pain 
is caused by its absorption." 

It is to be understood that these preparations and this method of 
pulp preservation are only to be utilized when reasons exist which 
would preclude the perfect cleansing and filling of canals. These 
reasons may be economic or the impracticability of thoroughly extir- 
pating all pulp remnants. Failing in perfect extirpation, the paste is 
to be packed into parts where the irremovable pulp remnants exist. 

Quite recently formalin and its isomeric modification paraform 
have been suggested for use as mummifying agents, with* some promise 
of satisfactory results, but these substances are still in the stage of ex- 
perimental study. The irritating nature of formalin suggests caution in 
its permanent application to pulps or pulp canals, as several cases of 
chemical necrosis of tissues about the teeth have been reported from the 
injudicious use of the drug in question. 

Topographical Anatomy of the Pulp Chambers and Canals. 

A familiarity with the topographical anatomy of pulp chambers and 
canals is an essential preliminary to their proper opening and cleansing. 
Figs. 401, 402, and 403 (see pp. 443-445) illustrate the average pulp- 
chamber forms. 

The following outline figures (Figs. 404-439) are exact reproductions 



Fig. 404. 



Fig. 405. 



& 



& 



Upper central incisor. 



Upper lateral incisor. 



of sections made of typical teeth which have been shown by comparison 

with numerous other sections to be about the average anatomical forms. 

The Upper Central Incisor. — The pulp chamber (Fig. 404) approxi- 



FORMS OF PULP CHAMBERS AND CANALS. 



447 



mates in form that of the tooth itself. The opening of the canal is 
seen to be almost circular, and in the central axis of the tooth. 

Upper Lateral Incisor. — The chamber of the lateral incisor (Fig. 405) 
has a similar form ; the canal exhibits a tendency to diverge from the 



Fig. 406. 



Fig. 40/ 



Fig. 408. 




Upper lateral incisors (Ottolengui). 

straight line toward the apical end (see Figs. 406-408). The entrance 
to the canal is nearly oval. 

Upper Canine. — The chamber of the upper canine is large and open 
and has an elliptical canal entrance (Fig. 409). The root of this tooth 



Fig. 409. 



Fig. 410. 



Fig. 411. 





Upper canines. 



may also deflect from the line of the general axis. 
bifurcation of the root is seen (Figs. 410, 411). 



In 



rare cases a 



Fig. 412. 



Fig. 413. 



Fig. 414. 






Upper first bicuspids. 

The upper first bicuspid very commonly exhibits a bifurcation of 
the roots which may extend to any distance toward the crown (Fig. 412). 
At its entrance the pulp canal has a dumb-bell form, the handle of the 
dumb-bell being much attenuated. The distinct canals may begin 
almost at the base of the chamber, or be evident only near the apices 



448 



THE TREATMENT AND FILLING OF ROOT CANALS. 



of the roots. Two distinct canals may be present even in the absence 
of bifurcation of the root. The roots of this tooth may be much curved. 
Fig. 413 presents a condition occasionally seen : a trifurcation of the 
root of a bicuspid. Fig. 414 represents a section through the buccal 
roots; Fig. 414 also shows the neck section of the tooth. In the same 
mouth were found three bicuspids exhibiting the same condition. The 
bifurcated cuspid, Fig. 411, was from the same denture. 

Upper Second Bicuspid. — Sections of two typical forms of upper 
second bicuspid are shown in Fig. 415, a and b. In such a case as b — 
far from uncommon — it will readily be seen what dangers exist as to 
the difficulty of perfectly filling the flat general canal beyond the ellip- 
tical obstruction. The neck section in both types is almost alike. 

Upper First Molar. — The neck section of the upper first molar 



Fig. 415. 



Fig. 416. 





b a 

Upper second bicuspid. 



b a 

Upper first molar. 



(Fig. 416, a) shows a free entrance to the palatal root; the anterior 
buccal root has a triangular entrance, near the mesio-buccal angle of 
the tooth. The entrance to the disto-buccal root is very small; b, Fig. 
41 6, shows a section through the buccal roots of the tooth. Cases are 
occasionally seen where a short crown is associated with very long and 
divergent roots (Fig. 417). 



Fig. 41 




Fig. 418. 



Fig. 419. 





Upper molar. 



Upper second molars. 



Upper Second Molar. — The arrangement of canals in the second 
upper molar (Fig. 418, a) is much like that in the first; except that 
the tooth has a compressed form which brings the canal entrances closer 
together. A section through the buccal roots is seen in Fig. 418, b. 
This tooth occasionally presents marked aberrations in the location and 



FORMS OF PULP CHAMBERS AND CANALS. 



449 



distribution of pulp canals. Fig. 419 illustrates a case in which there 
was a trifurcation of the palatal root. Other abnormalities of the canals 
of upper molars are shown in Figs. 420-425 (Ottolengui x ). 



Fig. 420. 




Fig. 421. 




Fig. 422. 




Fig. 423. 



Fig. 424. 



Fig. 425. 






Upper molars (Ottolengui). 



Upper Third Molar. — The three roots of the upper third molar are 
frequently compressed together, giving the external appearance of a 



Fig. 426. 





Upper third molars. 



single round conical root. In many instances there will be found but 
a single large canal, as in Fig. 426, a. The rule is three canals, as 



Fig. 427. 



Fig. 428. 



Fig. 429. 





Lower incisors and canine. 



shown in Fig. 426, 6, which shows also a section through the buccal 
roots. The root is generally curved backward more or less. 

1 Methods of Filling Teeth. 
29 



450 



THE TREATMENT AND FILLING OF ROOT CANALS. 



Lower Anterior Teeth. — The forms of the canals and canal entrances 
to the lower anterior teeth are shown in Figs. 427-429. The form 
of partial canal bifurcation shown in Figs. 428 and 429 is noted 
frequently in longitudinal sections of typical teeth. 

Lower Bicuspids. — The forms of the canals in the lower bicuspids 
are much alike; the canal of the first, however, exhibits a tendency to 
the dumb-bell form of entrance (Figs. 430, 431). Tortuosities of the 



Fig. 430. 



Fig. 431. 




Lower first bicuspid. 



Lower second bicuspid. 



canal are far from uncommon, many of them of such nature as to ren- 
der full and complete entrance to their ends next to impossible ; in 



Fig. 432. 



Fig. 433. 



Fig. 434. 






Lower bicuspids. 



Fig. 432 the root was of corkscrew form, in Fig. 433 bent at right 
angles, and in Fig. 434 a short crown is associated with an extremely 
long and bent root. 



Fig. 435. 



© 




Lower first molars. 



Lower First Molar. — The lower first molar usually presents two 
canals : a large open canal for the posterior root, as seen in Fig. 435, 
a and 6, while the anterior root presents a flat ribbon-like canal very 



FORMS OF PULP CHAMBERS AND CANALS. 



451 



difficult of entrance. A transverse longitudinal section of the ante- 
rior root is shown in Fig. 435, c. In order to effect an entrance to 
the majority of these canals it is absolutely essential that the rubber 
dam be applied and the tooth well dried. A section through both roots 
is shown in Fig. 435, b. Not uncommonly two distinct anterior canals 
are found, and in rare instances two distal roots may be present, as 
shown in Fig. 435, d. The roots of this tooth, as those of the other 
lower molars, as a rule, bend backward. Fig. 436 (from Ottolengui) 
shows an exaggeration of this bending. 

This tooth not infrequently requires canal treatment before the roots 
are fully formed. A section through the anterior half of an immature 



Fig. 436. 



Fig. 437. 






Lower first molar. 



a b 

Lower first molar, immature. 



tooth is shown in Fig. 437, a; through the posterior half, Fig. 437, 6. 

Lower Second Molar. — A section of the lower second molar resem- 
bles that of the first, but distinct double canals in the anterior root are 
more frequently seen, as shown in the section of the anterior half in 
Fig. 438, b. 

Lower Third Molar. — In the lower third molar the roots are fre- 
quently compressed together, exhibiting bifurcation toward their apices 
(Fig. 439). 



Fig. 438. 



Fig. 439. 





a b 

Lower second molar. 




Lower third molar. 



The canals of any tooth may exhibit constrictions or flexions at any 
points of their lengths. Although there is no absolute indication as to 
the presence of flexions or abnormal lengths, an examination of the 
overlying gum should always be made, when lengths and irregularities 
may possibly be determined if the gum tissue and alveolar wall be very 



452 THE TREATMENT AND FILLING OF ROOT CANALS. 

thin. If any of these irregularities be present it is important that they 
be discovered and additional care be taken to effect a complete entrance 
to the canals. 

Instruments for Canal Treatment. 

The description thus far has included the territory to be operated 
upon and its condition as regards sepsis, the agents commonly employed 
to produce asepsis and antisepsis, and those applied to maintain these 
conditions. The first, the condition of the root canals and dentin ; the 
second, the various antiseptics employed therein ; the third, the several 
materials used as canal fillings. The next study includes the instru- 
ments employed and their specific applications. 

The first are enamel chisels. These are employed to cut down weak 
unsupported enamel walls and those portions of enamel removable by 
such instruments, which interfere with direct access to the pulp canals. 
The next, burs, of several forms ; the first, that known as the " dentate 
fissure bur," for cutting enamel ; next rose, inverted cone, and oval forms 
for enlarging cavities and removing infected dentin. Next, several 
forms of broaches, canal cleansers, and probes, Gates-Grlidden reamers 
for enlarging canals ; syringes, pluggers, and finally rubber dam and the 
appropriate selection of clamps. 

In relation with this latter device, it is to be recalled that demon- 
strations have shown the saliva to be a highly infective fluid, for the 
reason that it contains a variety of pathogenic organisms which must be 
excluded from pulp canals if asepsis of these passages is hoped for. No 
other single means serves so effectively as isolation by the rubber dam. 

A variety of syringes will be required, a large instrument for irriga- 
tion (Fig. 440), to wash away loose debris which may be present in the 
cavities ; smaller syringes will be required to accurately place definite 
quantities of medicaments in canals (Figs. 441, 442, and 443). 

Dentate fissure burs are invaluable instruments for removing por- 
tions of sound enamel walls which interfere with direct access to the 
root canals. Cutting from within outward, giving the bur a sawing 
motion, a groove may in a few minutes be extended across the occlusal 
face of a molar from a distal cavity to a point directly over the ante- 
rior root. 

Large rose, inverted cone, and oval burs are employed to remove 
the dentin which may obstruct direct entrance to the canals ; these are 
as a rule to be used with a draw-cut, placed first in the deepest portion 
of the cavity, and while revolving drawn toward the operator. Care is 
to be exercised that no more than necessary of the walls, particularly 
the floor of the pulp chamber, is to be burred away, to avoid mechan- 
ically weakening the tooth. 



INSTRUMENTS FOB CANAL TREATMENT. 



453 



The broaches employed are of several forms. A broach is, accurately 
speaking, an instrument designed to enlarge openings; so that the 



Fig. 440. 



Fig. 441. 



Fig. 442. 





Dental syringe. 



Minim syringe. 



J. X. Farrar's alveolar abscess syringe. 



barbed nerve broach is not employed as a broach but as a pulp-extrac- 
tor (Fig. 444). They and other forms of extractors (Fig. 445) are used 
to loosen and remove debris from canals. 



454 



THE TREATMENT AND FILLING OF BOOT CANALS. 
Fig. 443. 




Bulb syringe. 



The toughness of these instruments is remarkable. They are so tem- 
pered that they can be bent in any desired direction and when properly 
manipulated will readily follow a small and crooked canal to the apex 
without danger of breaking off. Two forms : with sharp hooks, for 



Fig. 444. 



Barbed pulp-extractors and holder. 

removing the pulp ; and straight, with the ends slightly roughened, 
for carrying a shred of cotton in cleansing out the canal or treat- 
ing alveolar abscess. 

The next instruments employed in this connection are what are 
known as Donaldson's pulp-canal cleansers (Fig. 446). The points of 
these palp-canal cleansers are reduced so as to enter the canal readily, 
and the barbs, which are cut of just sufficient depth to accomplish 
their work, are arranged spirally around the shaft, in effect forming a 
screw, so that no two cuts are exactly opposite each other (see enlarged 
view, a, Fig. 446). With ordinarily careful usage these cleansers will 
remove the pulp substance perfectly, without liability to be broken or 
to become fastened in the canal. If at any time the instrument does 
not withdraw readily from the root, a turn or two to the left (unscrew- 
ing) will at once release it. 

Made of tough steel piano-wire, with polished rubber handles ; also 
without handles, to be used in broach-holder. 

The enlarged view of the Gates-Glidden nerve-canal drill (Fig. 
447) shows the peculiarity of the safety Glidden point, which will not 



INSTRUMENTS FOR CANAL TREATMENT. 
Fig. 445. Fig. 446. 



455 



u 

Dr. Donaldson's pulp-canal cleansers. 






Dr. Donaldson's spring- 
tempered nerve-bristles. 



enlarge the canal, but will merely guide 
the drill into a canal no wider than itself, 
until it reaches the root-apex, through 
which only the sharp point will pass, and 
produce a sensation of pain that gives 
notice of its protrusion ; yet, unless the 
foramen is wider than the base of the 
guide, the Gates drill will not cut 
through the end of the root — a danger 
that the improved drill is specially 
designed to avoid. The reamers are 
made with their thinnest part near the 
junction of shaft and stem, so that 
should fracture of the tool occur, a long 
piece will be left protruding from the 
tooth and may be readily withdrawn. 
Using the series, one after the other, with care and judgment, even 
a tortuous canal may be suitably enlarged ; but it should be kept in 
mind that many roots are thin at their 
apical portions, and their canals, if much 
enlarged, may be cut through laterally ; 
hence the advisability of employing usu- 
ally the smaller sizes of drills, and always 
the smallest first when the canal is narrow. 
There is a diversity of opinion as to the 
wisdom and propriety of using reamers of 
any kind in pulp canals. They are con- 
demned in toto by some operators ; others advise their employment 
in all cases. 



Fig. 447. 



Improved Gates-Glidden nerve- 
canal drill for engine work. 



456 THE TREATMENT AND FILLING OF BOOT CANALS. 

The Cleansing of Canals. 

The student has been made familiar with the pathological conditions 
he is called upon to treat, and with his armamentarium, including the 
medicinal agents employed in their correction, and is now prepared to 
apply the one to the other. 

It is most apropos at this juncture that the arguments for and against 
the reaming of root canals should be reviewed. The valid objections 
urged against reaming as a routine practice are, first, the danger of 
encroachment upon the cementum by the reamer ; second, the breaking 
of the delicate reamers in the canal and the difficulty and often impos- 
sibility of removing the fragment when such accident occurs ; third, the 
liability of forming false canals by inability to confine the drill to the 
anatomical canal. The argument advanced in support of the practice is 
the direct and ready access attained by it to the length of the canal. 
Owing to the fineness and tortuosity of many canals it is impossible for 
the operator to assure himself that he has thoroughly cleansed and filled 
them ; by accurately and properly reaming the canals directly accessible 
to fine reamers they are given such form that a filling may be placed 
with a reasonable assurance that the apex is hermetically sealed. It is 
urged that as many roots — notably the anterior roots of lower molars, 
the anterior buccal roots of upper molars, the roots of upper bicuspids 
and of lower incisors — have a flattened form, their pulp canals have a 
ribbon form. In reaming such canals there is danger of the reamer 
impinging upon the cementum at the thin portion of the root. The 
advocate of root reaming, therefore, advises in such cases the employ- 
ment of Donaldson's canal cleansers to scrape away the canal walls, 
enlarging them uniformly. 

' The danger of breaking reamers is always an imminent one, al- 
though such accidents are commonly due either to poorly made or 
imperfectly tempered instruments, or to carelessness upon the part of 
the operator. Even the most skilful must be ever on the alert to detect 
any unusual resistance offered to the advance of the reamer. This 
danger increases if the direction of the canal diverges from a straight 
line. It is obvious that with any instrument which is being rotated, its 
point must be kept in line with its shaft to minimize the strain on the 
part immediately above the cutting portion. 

The employment of reamers is therefore advised only in nearly straight 
and rounded roots ; the central idea to keep in mind is that reamers are 
employed merely to uniformly enlarge canals which already exist, never 
to form new ones. Root canals which have a flattened form are en- 
larged by means of the cleansers, using progressively increasing sizes, 
and supplementing their action where and when necessary with sulfuric 



THE CLEANSING OF CANALS. 



457 



Fig. 448. 



acid, as advised by Dr. J. R. Callahan. 1 This method is of great value ; 
it furnishes a means for entering and thoroughly cleansing and enlarg- 
ing canals which before its introduction were regarded as impossible of 
entry. 

It has no doubt been observed by every operator, how seldom roots 
which have been well prepared for artificial crowns of the post variety 
become the seat of pericementitis. This fact sug- 
gests that the mechanical removal of the existing 
boundary walls of the root canals, by removing 
those portions of dentin invaded by septic organ- 
isms may lessen the opportunity of sepsis. Miller 
has shown 2 that this infection of dentin about 
canals is, as a rule, superficial (Fig. 448). The 
observations made in the essay of Dr. Miller 
show also that any danger to the lateral peri- 
cementum by invasion of the dentinal tubules 
leading from the root canal is remote in the 
extreme. Infection to some depth does occur, 
however (Fig. 449). It is undisputed that the 
source of septic infection of the pericementum 
is from the canals by way of the apical foramen, 

Fig. 449. 




Mi; ii\>)$ 


m 



m 



\ 



.'Hi 




Fig. 448.— Sector of a cross section from a diseased root : a, cement ; b, stratum granulosum 
c, very narrow and finely branched tubules ; d, infected district. (X 150.) 

Fig. 449.— Dentin from the root of an abscessed tooth, showing the penetration of cocci to e 
. depth of about & mm. (^ ff in.). The side a-b bordered upon the canal. (X 1000.) 



1 Proc. Ohio State Dental Society, 1894. 



Dental Cosmos, 1890, p. 353. 



458 THE TREATMENT AND FILLING OF BOOT CANALS. 

and if the tract there represented be made aseptic no trouble need b& 
feared. 

As the object in all succeeding operations is to remove and not to 
institute a septic condition, care must be exercised that no septic organ- 
isms be introduced by the operator into the field of operation. The 
first step is therefore the rendering aseptic of this field. The teeth 
should be cleansed first with a brush and soap, then the mouth be rinsed 
with an antiseptic, as 3 per cent, pyrozone, 10 per cent, solution of 
meditrina, or a lilac-colored solution of potassium permanganate. The 
instruments are to be sterilized, and to effect this object an excellent 
means is by dipping the mechanically cleansed instruments in strong 
ammonia water. 1 If any food or pulp debris occupy the pulp chamber it 
is to be washed away with the antiseptic employed to sterilize the mouth. 
The rubber dam is adjusted, and direct sterilization of the canals, and, 
when indicated, of the tissues at the apex of the root, is to be attained. 

Method of Entrance to Canals. — The first step or stage of the 
operation is the gaining of direct and free access to every canal of the 
tooth. This may at times appear to involve the removal of an undue 
amount of the crown of the tooth. Unfortunately this is true, but 
efforts at the conservation of too much of the crown structures and 
form are frequently followed by incomplete cleansing and filling of the 
canals. This latter is the greater evil of the two, so the cutting away 
of the crown is always to be done when necessary to accomplish the 
end in view. 

In the vast majority of cases in which it is necessary to remove a 
putrescent or septic pulp the carious process has invaded the crown of 
the tooth extensively ; the cavity of decay is therefore excavated until 
perfectly free from carious dentin ; weak enamel walls are dressed 
away by means of enamel chisels, and usually direct access to the pulp 
chamber is gained. This is still insufficient ; the cavity must be 
opened so that the finest size of canal bristle can be carried directly to 
the apex of the root without danger of fracturing the instrument. 

In central incisors, as the carious cavities usually open upon the 
approximal surfaces, entrance is gained to the pulp chamber by extend- 
ing at the palatal aspect of the cavity a groove from the cavity to 
over the entrance of the pulp chamber (a, Fig. 450). 

The same rule is observed with the lateral incisors and canines. 
Should the pulp have died subsequently to the insertion of fillings, 
which are mechanically faultless, entrance to the pulp canal is made in 
the basilar pit (b, Fig. 451). For canines the opening is made at a 
higher point, about one-third the way toward the cutting edge. These 
openings, while they should be large enough to afford free access to the 

1 See also Chapter IV. 



THE CLEANSING OF CANALS. 459 

canals, should not be made so large as to weaken the crown, or there is 
danger of fracturing it when in physiological use. 

Cavities in bicuspids invading the pulp are usually upon the ap- 
proximal surfaces ; they are to be extended over the occlusal face of 
the tooth until access to the canals may be had (see Fig. 452). 



Fig. 450. Fig. 451. ■ 

Fig. 452. 



Cavity in bicuspid. 



Fig. 453. 
a c 






The same procedures are to be followed in molar teeth. In lower 
molars if the .carious cavity be upon the distal wall, it is to be artificially 
lengthened across the occlusal face until the probe may be carried 
directly into each canal (Fig. 453, a) ; the same method is pursued if 
for a mesial cavity. In upper molars, especial care is required to gain 
primary access to the anterior buccal root, and tooth structure must be 
cut away until this access is secured (Fig. 453, b). Should the carious 
cavities open upon the buccal faces of the posterior or lingual faces of 
the anterior teeth, the upper cavity edge, that farthest from the gum,, 
must be extended toward the cutting edge of the tooth until a bent 
probe may be readily passed to the apex of each root (Fig. 453, c). In 
operating upon many, or most, of the canals of the posterior teeth it is 
necessary to bend the pulp extractor or canal cleanser until it is almost 
or quite at a right angle with the instrument carrier. 

In the six anterior lower teeth where openings are to be made in 
them in the absence of large cavities of decay, entrance is effected 
through the lingual wall. 

The advice of Dr. J. Foster Flagg is appended, as to the position 
of tap openings to be made in the several teeth, when the teeth if 
carious have not the carious cavity in such position as to afford access 
to the pulp chamber : 

" By means of a diamond drill or an inverted cone bur, a rougk 
spot is made in the centre of the face to be perforated ; this prevents 
slipping of the spear-pointed drill which is then employed to enter the 
pulp chamber. The outlines of the chamber are to be obliterated with 
burs." The dentate bur is a most effective means of enlarging such 
openings. " The opening is to be enlarged until a fine probe may be 



460 THE TREATMENT AND FILLING OF ROOT CANALS. 

passed into each canal ; the teeth are tapped in the following sit- 
uations : 

Upper Teeth. — Centrals and laterals : On the lingual face. 

Canines : On the tuberosity, or disto-labially. 

First or second bicuspids : On occlusal or buccal face. 

First molars : On occlusal, or, as a second choice, on buccal face. 

Second molars : On occlusal, mesio-occlusal, or buccal face. 

Third molars : On mesio-occlusal face. 

Lower Teeth. — Centrals and laterals : On lingual face just posterior 
to cutting edge. 

Canines : On disto-labial portion near the gum. 

Bicuspids : On mesio-buccal face. 

First, second, and third molars : On mesial, buccal, or mesio-occlu- 
sal face." 

Treatment of Canals. 

The tooth and adjacent teeth being isolated by the rubber dam, 
direct access to each canal having been gained, the tooth having its 
walls sterilized and each instrument which has been or is to be used 
being sterilized, the subsequent procedures depend entirely upon the 
condition of the pulp chamber, canals, and dentin (and perhaps the peri- 
cementum), as regards sepsis. One of the several conditions described 
in the opening of the chapter is present ; which of these it is, governs 
the therapeusis. 

First : A ease in which the pulp has been intentionally devitalized and 
extirpated. The pulp having been removed en masse it has carried with 
it, provided of course no organisms have been introduced during or subse- 
quent to its extirpation, all of the sources of infection. The remote 
danger is now the existence of small fragments of pulp tissue which 
if unremoved might form a soil for the development of organisms ob- 
taining entrance to them ; or blood may have escaped into the canals 
where the dead pulp was torn from its connection at the apex. These 
must both be removed. 

Hydrogen dioxid, being the agent which will most quickly and 
effectively disorganize the blood corpuscles, is carried into the canals 
and permitted to act for a few minutes, when it is absorbed by means of 
cotton, or taper twists of bibulous paper ; then canal cleansers, beginning 
with the smaller sizes, are employed to scrape the walls of the canals free 
of any adherent pulp shreds or odontoblasts which may have been torn 
off when the pulp was removed. Larger sizes are to succeed these 
until the caliber of the canal is made larger and smooth. If it be a 
round root and there be any interference with the passage of these 
instruments to the apex of the root, it is evident that the same difficulty 
would be found in carrying filling material to its apex. A judicious 



TREATMENT OF CANALS. 



461 



Fig. 454. 



reaming of the root removes this difficulty and is therefore done. That 
size of the Gates-Glidden reamer which will enter the canal readily is 
revolved by hand, or, if in the engine, is revolved very slowly, stopping 
the moment any resistance is felt. The reamer is frequently withdrawn 
to remove the de'bris which collects behind it. As soon as resistance 
is felt, a fine canal cleanser is passed beyond the point and the walls 
scraped, when the reamer is reapplied ; this alternation of instruments 
is continued until sensitivity shows that the point of the reamer has 
reached the pericementum. The next size of reamer is then employed 
to enlarge the canal uniformly. As soon as a canal is reamed a tem- 
porary dressing of alcohol on cotton is placed in it to prevent the ingress 
of debris from other canals — that is, if it be a tooth having two or more 
roots. In upper molars, the palatal, and in lower molars the distal, 
root is to be first cleansed and dressed. If the subject of operation be 
a single-rooted tooth, preparation is now made for hermetically sealing 
the apex and filling the canal ; if a multi-rooted tooth, the canal next in 
size is entered if the root be round as evidenced 
by the general shape of the canal. For example, 
the anterior roots of lower molars, the buccal roots 
of upper molars or of bicuspids, which exhibit a 
round opening, have usually but not always a 
rounded body ; those showing a ribbon-like out- 
line are likely to have a corresponding outward 
form. Any efforts at reaming such canals should 
be ' confined to that portion showing a rounded 
opening ; thus, if a lower molar, the finest reamer, 
rotated by hand, the device of Dr. W. W. Walker 
(Fig. 454), is employed to enter and enlarge the 
buccal and lingual extremities of the ribbon-like canals. Any further 
enlarging should be done with the canal cleansers. The same rule 
applies to the buccal roots of upper molars and to bicuspids. When 
any doubt exists, the enlarging should always be done with the cleansers 
instead of the reamers. 

Not infrequently cases are found in which the root canals, or one 
of them, may have such contracted caliber as to refuse entrance to the 
finest canal cleansers. As a rule, such canals will be found in the buc- 
cal roots of upper molars and the anterior root or roots of lower molars ; 
occasionally the bicuspids, particularly the upper first bicuspids, will 
exhibit this condition. It is in such cases that the method of cleansing 
and enlarging introduced by Dr. Callahan will be found effective. A 
rose bur is employed to form a small pit of which the entrance of the 
pulp canal is the centre. In this pit a drop of sulfuric acid, 50 per 
cent, solution, is placed ; immediately upon the contact of the acid the 




Walker pulp-canal 
reamers. 



462 THE TREATMENT AND FILLING OF BOOT CANALS. 

finest size of Donaldson canal cleanser is passed as far as it will go into 
the canal, the cleanser is inserted and partially withdrawn, scraping 
away the calcium sulfate formed by the action of the acid upon the cal- 
cium salts of the tooth. The acid is quickly neutralized and fresh 
applications are made drop by drop, the scraping and pumping with the 
cleanser being continued until the point of the instrument is felt to 
reach or pass the apical foramen. Any organic matter, such as filaments 
or minute fragments of pulp tissue, which may have been present in the 
canal is destroyed. This applies also to organic matter undergoing de- 
composition or to organisms which may be present. As there is no 
marked degree of force required in the operation it may be pursued 
even in cases of pericementitis or acute abscess, to gain direct and free 
entrance to the seat of morbid action, the focus of germ development. 

In the event of the operator being unable to detect through instru- 
mental means the openings of minute canals, Dr. Callahan advises that 
a pellet of cotton containing a minute portion of acid be placed over the 
probable situation of each canal and sealed in over night. The follow- 
ing day, when the rubber dam is applied and the cavity dried, the spot 
of application of acid will be represented by a small white area, in 
which, if a canal entrance exist, it will be represented by a black dot. 
A pit is made at this point and acid is applied, when entrance by cleansers 
is attempted ; should failure to gain entrance result, it is most probable 
that the canal is almost or quite obliterated with secondary deposits 
formed by a receding pulp, hence no future sepsis is probable. As 
soon as the cleanser is felt to touch or pass the apical foramen the 
canals are syringed out with a saturated solution of sodium bicarbonate. 
Carbon dioxid is disengaged, which drives the debris left in the canals 
into the pulp chamber, and the acid is neutralized. 
, Thus far has been described the entrance to and thorough cleansing 
and uniform enlarging of canals of a tooth from which the intentionally 
devitalized pulp has been extracted ; the immediate question is, What 
treatment shall now be pursued ? Owing to the method of pulp with- 
drawal, the contents of the dentinal tubules are as yet chemically un- 
changed ; and it scarcely requires argument to demonstrate that, can 
they be kept in a stable condition, they constitute the best material for 
occupancy of the tubules. Examining the list of medicaments applica- 
ble as preservatives zinc chlorid is the agent fixed upon as the one 
which will best procure an unchangeable condition of the contents of 
the tubules. The experiments of Prof. Jas. Truman l have shown that 
this agent quickly diffuses through a capillary tube containing albumin, 
converting it into a whitish coagulum, an albuminate of zinc, which 
every anatomist knows to be one of the most efficient of all preserva- 

1 Proc. Academy of Stomatology, Philadelphia, 1894. 



THE ROOT-CANAL FILLING. 463 

lives. Anatomical specimens of parts injected with a zinc chloric! 
solution, and which have been subjected to all the conditions known to 
favor the development of putrefaction, remained unchanged after the 
lapse of years. It is advised, therefore — advice endorsed by a majority 
percentage of operators — that a solution of zinc chlorid be now placed 
in each canal. A twist of absorbent cotton is dipped in a solution of 
the salt. Should the apical foramen be large, a weak solution, about 
10 per cent., is employed; if fine,. the strength of the solution may be 
40 per cent. Unless carelessly manipulated or too great an excess of 
the coagulant be employed there is but little danger of forcing the solu- 
tion beyond the apex of the root. After about ten or fifteen minutes 
the application is withdrawn and cotton or paper cones passed in the 
canal to absorb any excess of the chlorid which may be present, and the 
canals are now ready for filling. 

The Root-canal Filling. 

When oxy chlorid of zinc has been determined upon as the perma- 
nent canal filling, the preliminary treatment of the canal with zinc 
chlorid solution is superfluous, as the coagulating and antiseptic action 
of the zinc chlorid used in making the oxychlorid cement fully answers 
the purpose in the short period of time elapsing before chemical com- 
bination of the fluid and powder results in a hardened body. 

Examining the available statistics regarding the several materials 
which have been employed for canal filling in such cases, there is found 
a greater percentage of success — that is, a fewer number of cases pres- 
ent subsequent evidences of sepsis — when zinc oxychlorid has been used. 
This is quite in accord with rational therapeusis ; the material is capable 
of hermetically sealing the apex and is unchangeable in the conditions 
surrounding it. Its antiseptic action probably plays little or no con- 
tinued part, disappearing shortly after the material sets ; it is, however, 
indisputable that when this material has been employed as a pulp cap- 
ping it has not infrequently converted the entire pulp into a hyaline 
coagulum which has remained permanently aseptic. 

This material is mentioned first on account of the ease, readiness, and 
certainty with which it may be placed. 

Gidta-percha ranks second in point of favor as a canal filling; this 
not on account of any deficiency of specific properties contraindicating 
its use, but there is not the same certainty of accurate placement and 
hermetic sealing as with the oxychlorid. Gold and tin, the remain- 
ing materials which have found any extensive employment in such 
cases, are open to the same common objection, viz. difficulty of manipu- 
lation. 



464 THE TREATMENT ANH FILLING OF ROOT CANALS. 

These are the practically irremovable materials. The removable 
materials which have been recommended are, first — 

Cotton. — It is due to Prof. J. Foster Flagg that this substance has 
been extensively employed, not as a filling material per se, but as a 
medium holding an antiseptic. The variety of cotton employed is the 
crude uncarded cotton wool. Dr. Flagg cites as a proof of the imper- 
meability of this material when properly packed, that bales of cotton 
which have floated in sea-water for long periods, when opened show no- 
evidences of moisture in their interior. 

Evidence regarding the value and danger of this material is con- 
flicting. It is asserted by the advocates of cotton canal fillings that, 
properly inserted, they remain unchanged for long periods, are readily 
packed into position, and if necessity demand may be readily removed. 
Those who oppose the use of cotton assert that it soon becomes filled 
with products of decomposition, and that after some years the texture 
of the material is destroyed, rendering its removal very difficult. In 
consequence of these conflicting opinions, the weight of evidence being 
with those who oppose its use, cotton has found but limited endorsement. 

The other removable materials, salol and paraffin, are innovations 
too recent to determine their value and position as canal fillings. The 
reports regarding salol are sufficiently conflicting to warrant advising 
its use only in conjunction with a central mass of gutta-percha or tin 
points ; the salol filling the space between the gutta-percha or metal 
point and the walls of the canal. 

These are the arguments for and against the several materials ; the 
weight of evidence being largely in favor of, first, the oxychlorid of 
zinc ; and second, gutta-percha. 

The question is, now, When shall the canals be filled ? Shall it be 
done immediately, or shall a period be permitted to elapse for assurance 
that no inflammatory action shall arise and the filling be a bar to its 
prompt reduction ? There are two causes which might be productive 
of inflammatory action : First, the dental manipulations of removing- 
the pulp and cleansing the canals might be productive of sufficient 
irritation to give rise to inflammatory reaction ; in that event the open 
canal would afford an escape for inflammatory effusions. The second- 
danger would depend upon whether septic organisms had been intro- 
duced or had not been thoroughly destroyed ; their sealing in the canals 
might be productive of septic inflammation. If the foregoing meas- 
ures of cleansing have been followed it is scarcely possible that any 
organisms could survive. General experience demonstrates that in but 
a small percentage of cases does the pericementum suffer markedly from 
traumatism during the cleansing and sterilizing of canals, so that the 



THE BOOT-CANAL FILLING. 465 

weight of evidence clearly teaches that such canals may be filled at 
once, and little or no reaction occur. 

Freshly mixed zinc oxychlorid being markedly irritating to vital 
tissues, it is usual to place between the paste and the tissues of the 
apical region a barrier to the former. This may be of gutta-percha. A 
very fine cone of gutta-percha about one-quarter inch long is dipped in 
oil of eucalyptus or oil of cajuput to soften it ; it is then carried to the 
apex of the root upon a fine probe and pressed into position. Or, a 
small pellet of cotton is dipped in a strong solution of thymol or aristol. 
It is extremely probable that when the freshly mixed oxychlorid is 
placed over it, the cotton becomes converted into amyloid which her- 
metically and permanently seals the apical foramen ; the same change 
occurs in the cotton upon which the oxychlorid is carried into position. 
Slender wisps of cotton are rolled thin enough to pass readily into the 
canals. A thin paste of oxychlorid is mixed, the cotton wisps are 
rolled in it until the meshes are full, when the extremity of a wisp is 
caught upon the end of a long, smooth, and slender canal plugger and 
carried up the canal to contact with the guard at the apex ; the plugger 
is withdrawn about one-eighth of an inch, and that length of the cotton 
is crimped upon itself; the remainder of the canal is plugged in the 
same manner until it is full, when the surplus length of the cotton is 
cut off and bibulous paper is pressed against the canal filling to absorb 
the surplus zinc chlorid. The floor of the pulp chamber may be covered 
with the stiffening paste from the mixing slab. 

A method by which cotton fiber loaded with the oxychlorid may be 
carried to the root apex with great accuracy and precision is as follows : 
The smallest size Donaldson bristle with smooth sides has its hooked 
end cut off with the scissors and the cut end made flat by rubbing 
lightly upon a fine Arkansas stone. This may be readily done by 
grasping the bristle very near to its point between the thumb and index 
finger and lightly rubbing it back and forth upon the surface of the 
stone. The bristle is then laid flat upon a glass slab and burnished 
from heel to point until the surface is perfectly smooth and any burr 
turned upon the point by the action of the burnisher is fully re- 
moved. A few fibers of cotton wool are then held between the thumb 
and index finger of the left hand, the direction of the fibers being in 
the line of the long axis of the index finger. The point of the prepared 
broach is then laid upon the cotton fibers, and both broach and cotton 
are rolled together between the finger and thumb. The rolling action 
of the finger and thumb serves to felt the cotton fiber on to the broach, 
and should be continued until the cotton is evenly felted over the 
squared end of the broach. The whole operation is done by the left 
hand. The broach is not twirled into the cotton with the right hand as 

30 



466 



THE TREATMENT AND FILLING OF ROOT CANALS. 



Fig. 455. 



is ordinarily clone where a roughened cotton-carrying probe is used. 

With a smooth broach and the cotton fiber felted on as described the 

broach may be pushed forward with considerable force into a canal 
without puncturing the cotton, which is securely carried as 
far as the broach will go. On account of the smoothness 
of the sides of the broach it may be easily withdrawn for 
a slight distance, and then engaging in the surrounding 
cotton it is used as a plugger to pack the cotton ahead of 
it, and the plugging action continues until the material is 
all packed in place. The adjustment of the cotton to the 
broach as described really forms a tube-like arrangement 
of the cotton with the instrument in its central lumen — 
an arrangement greatly favoring the operation of carrying 
the cotton into place and enabling the operator to use the 
cotton or any suitable fiber as a vehicle for canal dressings 
or for permanent filling in connection with the oxychlorid 
of zinc cement. 

If gutta-percha be the material selected for filling the 
canal, a careful examination is made to determine whether 
the apical foramen be comparatively large or very small ; 
in the latter case chloro-percha may be first pumped into 
the canals ; in the former it is wiser to omit the fluid, 
owing to the possibility of passing it through the apical 
foramen. In all cases where a canal filling is to be made 
of gutta-percha cones it is advisable to first lubricate the 
walls of the canal with one of the antiseptic oils, cinnamon, 
eucalyptus, or cajuput ; these will facilitate the passage of 
the point to the apex, and as solvents of gutta-percha will 
soften its surface and permit a more close adaptation to 
the canal walls. Should the apical foramen be found large 
enough to admit the pointed extremity of one of the gutta- 
percha cones, the end of the latter is cut off. The canal is 
lubricated with the oil, the cone itself dipped in the same 
medium, its base caught upon the end of a canal plugger, 
and it is passed carefully into the canal as far as it will go, 
when the plugger is withdrawn ; blasts of hot air from a 
hot-air syringe are directed against the exposed end of the 
cone until it is softened, and it is then pressed firmly into 
position by means of fine pluggers. A sufficient number 
of cones are added, softened and packed in position, filling 
the canal flush with the pulp chamber. 
In fine tortuous canals it is the usual practice to first pump them 

full of thin chloro-percha. A portion of the solution is caught be- 



Flagg's dress- 
ing pliers. 



THE ROOT-CANAL FILLING. 



467 



tween the points of a pair of Flagg's dressing pliers (Fig. 455) and car- 
ried to the opening of the canal, when, if the points are opened, the 
drop of fluid is deposited there ; it is then pumped into the canal by 
means of a fine smooth broach. To minimize the leakage due to the 
shrinkage of the chloro-percha in hardening, it is advised to thrust into 
the fluid material in the canal as large a gutta-percha cone as the canal 
will admit. Dr. Ottolengui advises that the pieces of silk described in 
the beginning of the chapter be used and an end left projecting into 
the pulp chamber, when, should removal of the filling ever become 
necessary, this end may be caught and the entire filling withdrawn. 

Should it be designed to fill the canal with gold, its exact length is 
measured by placing a small disk of rubber dam over a canal plugger, 
which may be carried to the apex, and inserting the plugger in the 
canal. The floor of the pulp chamber engages the rubber dam, and 
when the plugger point has reached the end of the canal the little gauge 
piece of rubber dam marks its exact length. Minute pieces of soft gold 
foil are cut, and one by one are carried to the end of the canal, the rubber 
upon the plugger being the guide to completeness of access to the root 
apex. This method is to-day rarely followed. Dr. W. S. How advises 
the use of shredded tin for sealing the apex of canals. By a series of 
fine probes the canal length is measured (as shown in Figs. 456-460), 



Fig. 456. 



Fig. 457. 



Fig. 458. 





and particles of shredded tin foil are carried to the apex and impacted 
by means of measured probes. 

Salol and paraffin are both manipulated after one manner. A very 
fine probe is passed into the canal to its apex ; a portion of the ma- 
terial is caught between the beaks of a pair of dressing pliers (Fig. 455) 
and held above an alcohol flame until it is melted, when the closed 
beaks are placed in the canal beside the probe, and opened, and the fluid 



468 



THE TREATMENT AND FILLING OF BOOT CANALS. 



material runs into the canal. Slowly withdrawing the probe, the fluid 
runs into the space occupied by the probe, filling the canal to the apex ; 
it is advisable, however, to warm a broach, and by a pumping motion 



Fig. 459. 



Fig. 460. 





insure the carrying of the filling to all parts of the canal. If salol be 
employed a cone of gutta-percha of such size as may be readily carried 
to the apex should be thrust into the fluid material, virtually filling the 
greater portion of the canal with gutta-percha. Several trustworthy 
observers have noted a disappearance of salol from canals in which it 
has been placed ; the gutta-percha minimizes the risk attendant upon 
such disappearance. The gutta-percha subserves another purpose : 
should it ever be necessary to remove the canal filling, blasts of warm 
air directed against the end of the gutta-percha may be made to melt 
the salol about it, when the cone may be readily withdrawn. This 
melting and withdrawal are more quickly accomplished if the central 
mass be of metal. 

Paraffin is unchangeable in the conditions under which it is placed. 



Treatment op Root Canals with Mummified Pulps. 

The remaining member of the aseptic cases is that of mummified 
pulp. So long as these cases remain perfectly aseptic they give rise to 
no symptoms and are, as a rule, uncovered by accident, rarely by design. 

Their usual history is as follows : At some time (perhaps years) 
before, an exposed or almost exposed pulp has been covered with a cap 
or cavity lining of the oxychlorid of zinc. They have remained com- 
fortable thereafter. At some subsequent time it may be necessary to 
open the tooth, usually on account of recurring caries : the total 
absence of dentinal sensitivity is noted, the tooth has changed color but 



SEPTIC CASES. 469 

little, if at all, and the operator burs carefully toward the pulp to 
determine its condition. (It should be remarked here that absence 
of dentinal sensitivity in a tooth having normal color and which con- 
tains a very large filling is an indication of aseptic death of the pulp, 
and the operator should renew all of his antiseptic precautions as to 
isolation of the tooth by the rubber dam and complete sterilization of 
all instruments and of the territory of operation.) The burring is con- 
tinued without any evidence of sensitivity, and the instrument is finally 
felt to pass into the pulp chamber. There is no odor, no escape of 
fluid, the pulp being found dry and shrivelled. If sterilized pulp 
extractors are passed into the canals, the remnants of the pulp may be 
withdrawn, exhibiting none of the usual signs of decomposition such as 
odor and confluent softening. 

It is highly improbable that any organisms are present, unless they 
should have been introduced by the operator from the exterior. The 
possibility of this occurring should prompt caution, for it is the expe- 
rience of many that although organisms have not been present in the 
canals, when introduced from without they find a fruitful soil for devel- 
opment. Reaction indicating infection may occur within a few hours or 
may be delayed for perhaps two days. This condition may arise even 
in connection with teeth whose pulps have died under a capping of 
zinc oxychlorid, from the fact that the quantity of zinc chlorid used in 
the capping material was insufficient to completely saturate the pulp 
tissue and render it permanently antiseptic. It is advisable, therefore, 
to cleanse the canals with some powerful and penetrating antiseptic to 
destroy any chance organisms and to insert a probationary though per- 
fect root filling until the time of danger has passed. The antiseptic 
which meets the indications is the ethereal 25 per cent, solution of 
hydrogen dioxid known as pyrozone, permitted to remain in the canals 
for several minutes. The canals are then dried, and for the temporary 
filling salol is the rational indication. At the expiration of three days 
if no evidences of pericementitis are present the operator may remove 
the salol, reapply the antiseptic, and fill the canals with oxychlorid or 
with gutta-percha. 

The use of formalin (40 per cent, aqueous solution of formic alde- 
hyde) should be mentioned in this connection. A 5 per cent, solution 
placed in the canals is a coagulant antiseptic which quickly and cer- 
tainly penetrates into and sterilizes the finest recesses. 

Septic Oases. 

The second great class of cases, the septic, comprises those in 
which the pulp has undergone some extent of decomposition. As a 
rule, the first organisms which invade pulp tissue are the staphylo- 



470 THE TREATMENT AND FILLING OF ROOT CANALS. 

cocci and streptococci, which find a suitable habitat in the live pulp. 
Advancing first along the lines of the veins, their toxic waste prod- 
ucts causing inflammation, the organisms invade, peptonize, and liquefy 
the inflammatory effusions. As these cocci advance toward the apex 
of the root, the necrotic and altered tissues which are left behind 
become the breeding-ground of other organisms, particularly the bacteria 
of putrefaction. The altered portions of pulp tissue are decomposed 
into products of progressively simpler chemical composition, until all 
of the albuminous substances have been transformed : first peptones are 
formed, further decomposition produces ptomains, next such bases as 
leucin, ty rosin, and the amines, together with fatty acids ; x finally the 
end products are hydrogen sulfid, ammonia, carbon dioxid, and water 
(see Fig. 398). "Fermentation and putrefaction can only occur where the 
fungi concerned live, and the extent of decomposition is conditioned by the 
number of fungi" (Ziegler). 

As there are several distinct types of decomposition, so is there a cor- 
responding number of varieties of organisms. The septic cases may be 
divided into two classes : First : Those in which septic invasion has not 
passed beyond the apical foramen and given evidence of pericemental 
irritation or inflammation, these tissues being threatened though not 
invaded. Second : Those in which the pericementum has become the 
seat of septic invasion. This latter class is subdivided according to the 
nature and extent of the septic processes : the first subdivision comprises 
cases of acute pericementitis non-purulent ; the second, of chronic peri- 
cementitis without evident pus formation ; the third, of purulent peri- 
cementitis, which may be either acute or chronic. 

1. In the first of the first class of these cases — those in which the 
suppurative process has invaded the pulp to near its end — the necrotic 
portions of the pulp are undergoing putrefactive decomposition. To- 
ward the end of the process, when the apical portion of the pulp is 
invaded, it is not uncommon to find evidences of pericemental irritation; 
this frequently ceases spontaneously, as though the irritation had caused 
the formation of a barrier between the tissues of the apical region 
and the suppurating pulp. An increasing discoloration of the dentin 
shows the contents of the dentinal tubules to be also undergoing de- 
composition. It is necessary to remove this mass, destroying the 
products, the causes, and the soil of decomposition : this without cariy- 
ing infection to the vital tissues beyond the apex. When the odor of 
hydrogen sulfid may be detected, it is evidence that the ultimate de- 
composition of albuminous matter is in progress. As it is quite prob- 
able and an imminent danger that organisms might, upon a broach 
injudiciously employed, be carried from the body of the putrescent 
1 Ziegler, General Pathology, 1895, p. 437, 



SEPTIC CASES. 471 

mass to the apex of the root, it is the part of wisdom and prudence to 
destroy the organisms as a primary measure. There is no quicker or 
effective means of destroying H 2 S, and probably the causes leading to 
its production, than applications of iodin. The reaction involved in 
the decomposition of H 2 S by iodin was pointed out by Dr. W. F. 
Litch : l "In passing a stream of hydrogen sulfid through tincture of 
iodin, the latter element seizes upon the hydrogen, forming hydriodic 
acid, which remains in solution, the sulfur falls as a precipitate ; the 
solution is decolorized." Any excess of iodin which remains may be 
readily removed by an application of ammonia water, a solution of 
ammonium iodid being formed which may be readily washed away. 

A penetrating antiseptic is now indicated, to sterilize to as great a 
depth as practicable. A 10 per cent, solution of formalin fulfils this 
indication. It is permitted to act for some time. The contents of the 
canal are scraped away, never pushing the broach by which the scraping 
is done, for fear of carrying organisms deeper into the canal. As the 
end of the canal is approached 5 per cent, formalin is substituted. 

As stated, septic canals contain certain fatty bodies and derivatives 
of albumin, together with more or less partially disorganized pulp tissue 
and a mixed bacterial infection. Examining the list of therapeutic 
agents it is seen that one of them, sodium dioxid, possesses properties 
capable of neutralizing each of the offending elements. This material 
may be employed either in the solid form or in solution. Solutions of 
sodium dioxid must be made with great care to prevent escape of the 
oxygen. A tumbler of distilled water is set in a vessel containing ice- 
water ; into the distilled water the sodium dioxid is dusted very slowly 
in small amounts. Each addition is attended by the evolution of heat. 2 
The sodium dioxid is added to the point of saturation, and reduced to 
the desired percentage strength by additions of distilled water. 3 

A drop of the saturated solution is placed upon a wisp of asbestos 
fiber (as it destroys cottou fiber) and is carried into the canal ; in a few 
moments the cavity may be syringed, and a deeper application of the 
dioxid solution made — this time of 50 per cent, solution. Each time 
the asbestos is removed it is seen that the discolored dentin surrounding 
the canal becomes whiter; the discoloring matter in the tubules has been 
destroyed. 

When a broach may be passed freely to the apex of the root, and 
the solution comes away clear from the root, sterilization is presumably 

1 Dental Cosmos, 1882. 

2 Dr. "Win. Trueman advises that the soldered lid of the can containing the oxid be 
perforated as a pepper caster, and the sodium dioxid shaken into the distilled water 
through the perforations. 

3 E. C. Kirk, Denial Cosmos, vol. xxxv. p. 195; F. T. Van AVoert, ibid., vol. xxxvi. 
p. 499. 



472 THE TREATMENT AND FILLING OF ROOT CANALS. 

complete. A 10 per cent, solution of sulfuric acid is pumped into the 
canals by means of iridium broaches ; this neutralizes any free alkali 
which may be present. The canal or canals are next washed out with 
hot distilled water, dried with cotton, filled with alcohol, and well dried 
by blasts of warm air. 

Many operators immediately and permanently fill such canals ; 
however, as there is the possibility that sterilization may not be abso- 
lute, it is the usual practice to fill the canals tentatively yet perfectly. 
Salol and a metallic point make an excellent canal filling in such 
cases. When the canals and dentinal walls are dried by means of the 
alcohol and warm blast they are filled with salol made very fluid, and 
the metallic point thrust into the canal containing it. Some slight 
pericemental disturbance may follow, but quickly subsides under the 
influence of a counter-irritant applied to the gum over the root (tr. 
iodin., tr. aconit. et chloroform, da. pars wq. The crown cavity is sealed 
with sticky temporary stopping for a few days, when if the condition 
of the pericementum is found normal, the salol filling is removed (if 
the operator desires) by heating a pair of tweezers and grasping the 
protruding end of the metal cone. It is the general practice to then 
fill the canal with oxychlorid or gutta-percha. 

Should the case present evidences of profound change in the contents 
of the tubules, i. e. much discoloration, the 50 per cent, solution of 
sodium dioxid may be sealed in the canal for a day ; the next day the 
canals are syringed freely with an acid solution of hydrogen dioxid. 
Dr. Kirk advises that the dentin be saturated with the sodium dioxid 
solution, then upon the addition of hydrochloric acid, hydrogen dioxid 
is formed wherever the sodium has penetrated, and drives out the soapy 
matters formed by the action of sodium hydroxid upon the products of 
decomposition. 

Preliminary to filling the canals it is the usual practice to fill them 
for a few minutes with an antiseptic, which will exercise an influence 
over a considerable period of time. Of all antiseptics, oil of cinnamon 
gives evidence of the most prolonged presence when so placed. 

Oases in which Pericementitis is Present. 

The next class for consideration includes the cases in which the 
tissues of the apical region are invaded. The first evidence of such 
invasion is tenderness of the tooth upon pressure. The cause of this is, 
no doubt, the inflammatory reaction of these tissues consequent upon con- 
tact and absorption of the waste products of organisms which are 
developing in the pulp canal. In the milder cases the tooth is sore to 
the touch, is slightly loose and extruded, and the gum over the affected 
root is redder than normal. Here, as in all grades of this disturbance, 



CASES IN WHICH PERICEMENTITIS IS PRESENT 473 

the aim is to get rid, first, of the causes of the inflammation ; second, 
when necessary to treat the inflammation itself. In entering the canals 
of such teeth — and of course they should be opened and cleansed as 
quickly and as thoroughly as possible — " The tooth should receive 
lateral support against the pressure of the burs used in excavating ; if 
the cavity be approximal the tip of a finger is placed against the face 
of the tooth on the opposite side to the bur. Should the direction 
of entrance be in a perpendicular line a ligature of linen twine having 
long ends may be tied tightly about the neck of the tooth, and traction 
exerted as a counter-pressure." l 

If the conditions permit, the cleansing and sterilizing are to be well 
done at once. Should the tooth be too tender to permit the usual 
manipulations, the gross mass is removed by treatment with sodium 
dioxid solution or by syringing with meditrina and stirring with 
broaches ; then a pellet of cotton saturated with lysol, a stronglv alka- 
line and penetrating cresol, is placed against the putrescent mass ; the 
gum is painted with iodin at a little distance from the site of the inflam- 
mation. When quiet is secured, the cleansing and sterilization of the 
canals should be thoroughly done ; and a dressing of a sedative anti- 
septic introduced. Campho-phenique or cinnamon oil answers well in 
this particular. 

In more pronounced cases the tenderness, extrusion, and looseness 
of the tooth are more marked ; in case the tooth should contain a filling 
beneath which a pulp has died — and this is a common history of such 
cases- — the release of the imprisoned mephitic gases is imperative. Ex- 
ercising counter-pressure, a very sharp and small spear-pointed drill is 
passed into the pulp chamber ; it may be necessary in cases of extreme 
soreness to effect this entrance at the neck of the tooth as the shortest 
path. After a few minutes the opening is syringed out with meditrina, 
and a blister is applied over the gum at a distance from the tooth, about 
two teeth posterior to it. The patient is directed to immediately take 
a hot mustard foot-bath, and to use frequently a 3 per cent, solution of 
pyrozone or other strong antiseptic solution as a mouth-wash. When 
the tooth is much extruded and is kept irritated by striking upon the 
occluding tooth, it is advisable to place a cap over the tooth posterior 
to the one affected. A cap may be readily made in a few minutes, by 
taking an impression in moldine or in plaster of the tooth to be capped, 
pouring a small die of fusible metal ; drive this into a block of soft 
lead, and then swage a piece of silver or German silver, !NTo. 26, to fit 
the die. This cap, covering the occlusal face and about half the walls 
of the tooth, is attached by means of zinc phosphate, thus securing 
surgical rest for the affected tooth. It was at one time a general prac- 
1 J. Foster Flagg's Lectures. 



474 THE TREATMENT AND FILLING OF BOOT CANALS. 

tice to permit the vent hole drilled at the neck of a tooth to remain 
open for the escape of the gases of decomposition, consequently the 
cases were in a constant state of sepsis. The practice is obsolete and 
is to be unqualifiedly condemned. 

In cases where the inflammatory action runs high, the tooth is ex- 
tremely tender, much extruded, and loose, the gum over the tooth be- 
comes livid, the pulse increases, there is some, and it may be marked, 
febrile action, the tongue is coated and the breath offensive. Energetic 
measures are necessary to avert necrotic action in the apical tissues. 
In this, as indeed in all cases without exception, the promptness and 
thoroughness of relief depends primarily upon the thoroughness with 
which the exciting cause of the inflammation is removed, i. e. the septic 
contents of the pulp chamber. In any case where direct access may be 
had to the canals, and this is very frequently the case, every effort short 
of that producing great suffering to the patient should be employed to 
wash away and broach away the putrescent material, using, where ne- 
cessary, sulfuric acid to enter the canals, powerful antiseptics always 
preceding the broach. Lysol is an excellent medicament in this con- 
nection, and campho-phenique another. The canal is syringed freely 
and repeatedly with 3 per cent, pyrozone, which should also be used as 
an antiseptic mouth-wash. Local bloodletting, as advised by Dr. G. V. 
Black, 1 is frequently an effective means for securing relief. Make a 
deep cut in the gum, clear to the process, the incision to be about one- 
quarter inch from the margin of the gum and encircling the neck of the 
tooth ; this will tend toward unloading the engorged vessels of the apical 
region. Dry cups over the face and to the neck, and always hot mus- 
tard foot-baths, are valuable adjuncts. 

Should the inflammatory disturbance run high, and a full, bounding 
pulse, coated tongue, marked fever, constipation, headache, and other 
febrile symptoms appear, attempts should still be made to abort the 
inflammatory action. After as thorough a cleansing of canals and anti- 
septic washing as possible under the circumstances, local bloodletting 
as described and advised by Dr. Litch 2 is efficient, by means of Swedish 
leeches, washing the gum, touching it with sugar, then applying the 
leech, which should be first placed in a test-tube, the mouth of the tube 
then being placed over the gum ; when the leech is gorged, it drops back 
into the tube. The mouth is then rinsed with warm water, to continue 
the bleeding. Quinin in doses never less than gr. vj is given in the hope 
of limiting the exudation into the inflamed area. As one of the best and 
most effective means of derivation is the induction of watery alvine dis- 
charges, the patient may be directed to take a saline cathartic or a rectal 

1 American System of Dentistry, vol. i. p. 927. 

2 Ibid., vol. i. p. 928. 



CASES IN WHICH PERICEMENTITIS IS PRESENT. 475 

injection of half an ounce of pure glycerin. If the pulse remain full and 
bounding, and headache persist, tr. aconiti or tr. veratri viridis is to 
be used as an arterial sedative, gtt. j of the tr. aconiti rad., or gtt. ij of 
the tr. veratri viridis, repeated every hour, until the pulse slows and 
lessens in volume and tension. At bedtime, if the inflammation be not 
markedly lessened, a sedative diaphoretic is administered, Dover's pow- 
der in full dose, gr. x, given in hot lemonade ; while the patient is drink- 
ing the latter he or she is to be well wrapped in hot blankets and the 
feet and legs immersed in a hot mustard foot-bath. The following 
morning a saline cathartic — magnesise sulph. 3ss — is given in a goblet 
of water. These directions (substantially those given by Dr. Litch, 
ibid.), may be followed with gratifying results in many cases ; even 
when the inflammation is not aborted, its violence is almost invariably 
lessened. 

Should the inflammation remain at its height for more than twenty- 
four hours, it is almost certain that pus has formed, and the indication 
is to give it exit. A spear-pointed bistoury is thrust through the gum 
over the apex of the affected root with such decided force as to pene- 
trate the process if possible. In the event of not accomplishing this 
end, the point of a spear-head drill revolving very rapidly is passed 
through the process to the apical region. Although this operation may 
be performed very quickly it may be necessary to administer nitrous 
oxid to quiet the patient and render the drilling painless. Anesthesia 
may be secured by means of the injection of a drop of a 15 per cent, 
solution of cocain. Dr. Black has described a painless method of effect- 
ing an entrance to the apical region. 1 A napkin is placed about the 
parts, the gum dried and touched at the point of election with a drop of 
95 per cent, solution of carbolic acid (trichloracetic acid full strength 
may be used). The necrosed membrane is scraped away by means of a 
coarsely serrated plugger until sensation is felt, when another drop of 
acid is applied, and the scratching is resumed until the bone is laid 
bare ; a sharp chisel is then used to open the apical region. No blood 
should be drawn during the operation except at the last step. 

The case in its present stage belongs to and is described in the suc- 
ceeding chapter, upon Alveolar Abscess. In any case presenting in 
which there is reason to believe the patient is the victim of syphilis — 
and alveolar periostitis is an occasional accompaniment of tertiary syphi- 
lis 2 — the use of large doses of potassium iodid is imperatively indicated. 
Unless decided measures are taken to abort such cases — and the usual 
antiphlogistic measures are of little avail — dangerous involvement of 
the general periosteum may occur, leading to necrosis. Not less than 

1 American System of Dentistry, vol. i. p. 928. 

2 See case — Heath, Injuries and Diseases of the Jaws, 3d edition. 



476 THE TREATMENT AND FILLING OF BOOT CANALS. 

gr. vj doses of potassium iodid are to be administered every three hours. 
Should there be evidence of detachment of the periosteum, evidenced by 
boggy swelling, a bistoury is to be passed boldly to the bone, making a 
large and free incision. 

Treatment of Chronic Pericementitis. 

The most usual form of chronic apical pericementitis is that associ- 
ated with pus formation. It will be discussed in the succeeding chapter 
under the head of Chronic Apical Abscess. 

A not inconsiderable number of cases may be seen in which pus 
formation is not evident and yet a chronic inflammation is present in 
the tissues of the apical region. If the pulp chamber be open the 
cause is evident, and its treatment has been described. A not inconsid- 
erable number of cases are due to malocclusion. This point is to be 
carefully observed, for it frequently affects teeth containing vital pulps 
and free from caries. The tooth is slightly loose and sore to pressure. 
Examination reveals abnormal occlusion, either too severe or in the 
wrong direction. Should the tooth contain a filling, it usually gives a 
normal response to applications of heat and cold ; examining the filling 
a spot is seen marking excessive occlusion ; in both cases grinding off 
the redundant tooth structure or filling and applying a counter-irritant 
over the apex subdues the inflammation. Its exciting cause being 
removed, it subsides. 

A class of cases is occasionally met with in which there is evidence 
of sluggish and persistent inflammation about the apices of pulpless 
teeth which have been filled ; acute inflammatory disturbance of a 
severe grade occurs but seldom. The most common cause of this con- 
tinued inflammation is probably the decomposition of a minute filament 
/ of pulp tissue which has not been removed from a canal ; or, again,, 
well-cleansed canals which have not been filled to the apex. Such 
cases are those of mild sepsis : perfect restoration to health is only pos- 
sible by re-cleansing, sterilizing and perfectly filling the canals. These 
teeth are always more or less hypersensitive even though it be unnoticed,, 
and therefore are not of a full measure of service until cured. 

Other cases in which there is reasonable assurance of perfect steril- 
ization and complete filling exhibit vascular sluggishness over the apex 
of the root. Continued and repeated massage is beneficial, 1 the disorder 
being apparently due to paralysis of vessel walls and not to septic 
causes. The tonus of the vessels may be improved by application of 
the galvanic current. This principle has wide application in general 
medicine and surgery. 

It is to be remembered that when the tissues about the apex of a 
1 Dr. W. F. Rehfuss, International Dental Journal, vol. xi. p. 581. 



TREATMENT OF CHRONIC PERICEMENTITIS. 477 

root have been irritated, it may be for months, by the products of a 
decomposing pulp, a series of degenerative changes may have occurred 
in them which require some time to remedy. Sterilization should be 
prolonged, and too hasty a stopping of the canal be avoided. In such 
cases, after each periodical treatment the canal should be dressed with 
some stimulant antiseptic : campho-phenique ; oil of cinnamon, or the 
admirable 1, 2, 3 mixture of Dr. Black : 

Oil of cinnamon, 1 part ; 

Carbolic acid, 2 parts ; 

Oil of wintergreen, 3 " 

Repeated applications of tr. aconit. et iodin. are to be made to 
iiie gums. 

A source of chronic apical pericementitis — frequently not detected 
until abscess has formed and discharged, it may be, at a distant point — 
is found in the death of a pulp from thrombus or jugulation. At some 
period the tooth has received a blow, or, it may be, has been moved 
too rapidly by a regulating appliance, or idiopathic pulpitis has occurred. 
Years afterward, a chance examination may reveal a deeper color of 
the gum overlying the tooth than over the others ; by reflected light it 
shows an opacity or discoloration of the body of the tooth. It may be 
slightly sore to percussion, which elicits a dull sound. " Dead pulp " is 
diagnosticated ; the tooth is opened under extraordinary antiseptic pre- 
cautions and cleansed freely with sodium dioxid — the ideal material in 
this instance — dried, and filled at least tentatively with salol. 

Another class of cases in which a similar condition of the pulp is 
found consists of those in which a pulp has died from repeated thermal 
shock received through a metallic filling placed in too close proximity 
to it. Although constructive action resulting in secondary deposits is 
the usual consequence of such irritation, profound degenerative changes 
in the tissue of the pulp frequently occur at later periods. The treat- 
ment is the same as in the preceding case. 

Unless the degree of antisepsis stated be employed in cleansing the 
canals of such cases, an annoying and it may be an obstinate perice- 
mentitis is lighted up which is difficult to conquer. 

A word of caution should be spoken in regard to the importance of 
the removal of inflammatory troubles, particularly the subacute forms, 
which affect the apical pericementum. It is supposed and with good 
reason that not only may tumor formations have their beginning in 
chronic inflammations ; various reflex disturbances of sensation and of 
special sense may be traced to such sources ; but any inflammation 
having such an anatomical situation is a smouldering fire which may 
under certain systemic conditions become a pathological conflagration. 



CHAPTER XVIII. 

DENTO-ALVEOLAR ABSCESS. 
By Henry H. Burchard, M. D., D. D. S. 



Definition. — In describing the septic inflammation affecting the 
tissues of the apical region in the previous chapter, it was stated that a 
common result of the inflammatory action was cellular necrosis and pus 
formation ; this condition is known as alveolar abscess or dento-alveolar 



Although alveolar abscess affecting some other portion of the peri- 
cementum may and does occur without death of the pulp/ septic infec- 
tion and bacterial invasion of the tissues of the periapical region from 
infected pulp canals is the most common source and cause of the affec- 
tion. The term as technically applied refers to septic apical pericemen- 
titis. 

Causes of Dento-alveolar Abscess. 

The exciting" causes of the disease process will be found in the pyo- 
genic cocci and probably other pyogenic organisms which inhabit and 
develop in the deepest portions of the putrescent pulp, finding entrance 
to the periapical tissues through the apical foramen of the tooth. Dr. 
Schreier of Vienna found diplococcus pneumoniae to be the excitant of 
inflammation in seventeen out of twenty cases of dental periostitis 
examined by him. 2 The ptomains and other waste products formed as 
the result of the life processes of these organisms cause poisoning and 
debility of the cellular elements of the part. Even granting that the 
organisms are present as the exciting cause, there is another factor 
involved which determines to a great extent the occurrence, time of 
occurrence, and severity of the disease, i. e. the predisposing causes — 
including under this head the condition of the tissues which favors or 
deters the development of the organisms. 

Predisposing" Causes. — It is unquestionably true that different in- 
dividuals will exhibit in their tissues marked differences in the degree 

1 Cases reported in Proc. Academy of Stomatology of Philadelphia, 1895. 

2 Oesterr.-ungarische Viertelj. fur Zahnheilk., April 1893. 

479 



480 DENTO-ALVEOLAR ABSCESS. 

of resistance to the invasion of disease causes. It is a well-recognized 
axiom of pathology that one of the most potent antiseptics, if not the 
most potent, is the inherent resistance of healthy protoplasm ; that is, 
healthy tissues offer a barrier to the development of the exciting causes 
of disease, while tissues which are debilitated through any of the many 
causes that affect them exhibit a diminished resistance to the invasion 
of the causes of acute disease. 

Prominent among the causes which favor the development and ex- 
tension of pyogenic processes are the inherited conditions indefinitely 
classified as strumous. The tissues of children having a family history 
of, for example, syphilis or tuberculosis, frequently exhibit evidences 
of lack of vital resistance. They are attacked and readily succumb to 
agencies which affect children of healthy parentage but slightly if at all. 
Inflammations about the teeth or of the soft tissues of the mouth run a 
severe course ; septic affections of the pericementum are attended by 
involvement of neighboring lymphatics and by evidences of septic 
intoxication. These predispositions may persist throughout the life of 
the individual ; as a rule, however, they grow less pronounced or less 
-evident with age. 

Acquired cachectic conditions of the adult also form a strong pre- 
disposition to invasion of the tissues by pathogenic organisms. It is a 
matter of frequent observation that tuberculosis and, in a more pro- 
nounced degree, syphilis are constitutional conditions which markedly 
diminish the resistance of the tissues. Inflammatory disturbances 
which in an individual free from cachexia would probably be circum- 
scribed, when they occur in the cachectic are diffuse and virulent. 
Local predisposing causes consist of faulty hygiene, producing debility 
of the tissues, for it is noted that abscess is more likely to run a virulent 
course in unclean mouths than in those kept free from fermenting and 
putrefying masses ; this is a general, though not a universal truth. 

Pathology and Morbid Anatomy. 

The pathology of septic pericementitis has been described in Chapter 
XVII. That of alveolar abscess begins as soon as there is death of 
cellular elements in the exudation. The exudation is liquefied in the 
focus of the inflammation by the action of ferments ; the leucocytes are 
invaded by and strive to devour the pyogenic cocci which are present — 
the species of warfare described by Metchnikofif; the leucocytes 
succumb, die, and form pus corpuscles, which are found to contain the 
pyogenic cocci. The cellular exudate is then broken down into a 
granular detritus, which, with the dead corpuscles and peptonized effu- 
sion, constitutes pus. 

The diplococcus of pneumonia is said to be a constant attendant 



PATHOLOGY AND MORBID ANATOMY. 481 

on alveolar abscess, and this particular organism is believed by 
Schreier to be the usual excitant of the inflammatory action in these 
cases. 

The primary seat of the abscess is usually in the pericementum, 
between its attachment to the cementum and its attachment to the 
alveolus. From the central cavity of softening the necrotic process 
spreads peripherally ; cell by cell the inflammatory wall forming the 
outlines of the abscess and the exudates are liquefied and the cavity 
grows larger. The cancellated bone about the apex of the root is in- 
volved and becomes the seat of osteomyelitis and molecular necrosis. 
Larger and larger grows the volume of the abscess until the periosteum 
covering the alveolar process is involved, softened, and raised from the 
bone. The inflammatory action precedes the advance of the pus along 
the line of least resistance ; and if it run high the periosteum may be 
softened over quite an extensive area and raised from the bone by the 
exudation beneath it. The pus penetrating the periosteum, the soft tis- 
sues are involved and softened, when the pus breaks through the mu- 
cous membrane, discharging usually by the shortest route from the 
abscess to the exterior. The progress of septic destruction is along the 
line of least resistance, and although as a rule this points upon the ex- 
ternal surface of the gum immediately above the apex of the affected 
root, it may follow other directions. In some cases the pus finds exit 
through the pulp canal of the affected tooth, forming what is commonly 
though incorrectly known as blind abscess. This form of abscess dif- 
fers from that with external fistula as a result of its mode of formation 
rather than because of any essential difference in its pathology. The 
history of an acute inflammatory stage is usually absent or it has caused 
but slight disturbance. Invasion of the apical pericementum by bac- 
teria has been slow and superficial and the inflammatory reaction 
restricted to the tissue immediately surrounding the apical foramen ; 
the necrotic process has been ulcerative in character, molecular death 
of the membrane taking place slowly until the tissue about the foramen 
is lost and the denuded apex projects into a necrotic cavity which allows 
of drainage of its contents through the foramen and root canal. In 
these cases the abscess cavity is usually comparatively small, and the 
inflammatory action is less severe than when the pus has a longer path 
of exit (see Fig. 461). 

The pus may exhibit evidences of semi-encystment. Collections 
may apparently remain in the tissues of the gum for long periods with- 
out fistula. A case in practice presented conditions similar to that 
exhibited in the illustration (Fig. 462) ; it had existed for several years 
about a replanted tooth, and responded promptly to treatment. 

In other cases the line of tissue destruction and pus escape is along 

31 



482 



DENTO-ALVEOLAR ABSCESS. 



the pericementum, the pus discharging at the neck of the affected tooth. 
Many of these cases occur 
in connection with pulpless 
teeth which have elongated, 
or those in which there has 
already been loss of peri- 
cementum. 

Abscesses upon the upper 
central or lateral incisors may 

Fig. 461. 





Blind abscess at the root of an upper 
incisor (Black) : a, abscess cavity 
in bone; b, drill hole exposing the 
pulp chamber for treatment. 



Acute alveolar abscess of a lower incisor with pus cav- 
ity between the bone and. the periosteum (Black) : 
a, pus cavity in the bone ; b, pus between the peri- 
osteum and bone ; c, lip : d, tooth ; e, tongue. 



perforate the nasal floor (see Fig. 463). After a period of marked perice- 

Fig. 464. 





Alveolar abscess at the root of 
a superior incisor discharging 
into the nose (Black) ; a, large 
abscess cavity in the bone ; b, 
mouth of fistula on the floor of 
nostril ; c, lip ; d, tooth. 



Alveolar abscess at the root of an upper 
molar discharging into the antrum of 
Highmore (Black): a, abscess cavity in 
the bone; b, mouth of fistula on the 
floor of the antrum ; c, pus in the antral 
cavity. 



mental disturbance, the inflammatory action running high, causing pain 
and swelling of the nostril of the same side, the symptoms may suddenly 



PATHOLOGY AND MORBID ANATOMY. 



483 



abate without any evident signs of pus having been discharged. Soon 
after a purulent discharge may be noted from the nostril, leading to the 
belief that purulent nasal catarrh (ozena) is present ; many of these cases 
are diagnosed and treated as ozena. In injection of the pulpless incisor, 
particularly with pyrozone, the pus and fluid are seen to emerge from the 
nostril, exhibiting the true source of the pus. Abscesses upon upper 
second bicuspids and molars may perforate the floor of the antrum 
(Fig. 464). 

In the lower jaw the pus may pass out of the alveolar process and 

Fig. 465. Fig. 466. 





Chronic alveolar abscess at the root of a lower incisor 
with a fistula discharging on the face under the 
chin (Black) : o, abscess cavity in the bone ; 6, b, b, 
fistula following in the periosteum down to the 
lower margin of the body of the bone and dis- 
charging on the skin. 



Chronic alveolar abscess of the root of 
a lower incisor with abscess cavity 
passing through the body of the bone 
and discharging on the skin beneath 
the chin (Black) : a, very large ab- 
scess cavity ; b, mouth of the fistula. 



fail to perforate the overlying soft tissues, pursuing a path which may 
lead to its exit upon the face beneath the jaw or chin (Fig. 465). In 
others the pus may burrow through the body of the bone and open 
upon the face. (See Figs. 466, 467.) 

In a case of persistent fistula opening upon the side of the face over 
the body of the lower maxilla, there was no evidence of inflammatory 
disturbance in the edentulous gum. An exploratory incision, made at 
a point indicated by a probe passed into the sinus, revealed the presence 
of a small root-fragment. Healing of the fistula was spontaneous upon 
its removal. Prof. M. H. Oyer 1 records a case of abscess opening 
1 Proc. Academy of Stomatology, 1896. 



484 



DENTO-ALVEOLAR ABSCESS. 



over the body of the lower maxilla immediately anterior to the groove 
for the facial artery (Fig. 468). A flexible probe passed into the fistula 



Fig. 467. 



Fig. 468. 





Fistula passing down through the body of the 
lower maxilla (Black). 



Abscess with tortuous sinus opening upmi 
the face: A, tissue of cheek; B, floor 
of mouth ; C, abscess tract. 



appeared to enter the submaxillary triangle ; in the absence of evident 
dental cause, the case had been diagnosticated and treated as abscess of 
the submaxillary gland. The direction taken by the probe gave no 
indication of a tooth being involved. The usual therapeutic measures 
applied to a submaxillary abscess proving unavailing, a serial examina- 
tion, one of many, of the teeth of that side was made. In one tooth, the 
second molar, was a large amalgam filling. The pulp responded, though 
feebly, to the usual tests for vitality ; upon entrance to the tooth the 
anterior portion of the pulp was found partially vital, the posterior 
portion dead and decomposing. The pulp was removed ; antiseptics 
were pumped through the posterior root, found exit at the fistula, and 
the causal relation of the putrescent pulp and the abscess was shown 
by a prompt disappearance of the disease. 

In one case of abscess upon a lower third molar, the pus made en- 
trance into the tissues about the insertion of the internal pterygoid 
muscle. Cases have been recorded in which the pus from abscess about 
a lower molar has burrowed through the bone and, caught beneath the 
platysma myoides muscle, it has passed down the muscle, discharging 
from an opening upon the neck or upon the shoulder. 

Abscess upon an upper molar may find exit upon the face beneath the 
malar bone. Occasionally the duct of Steno may be involved in the 
abscess tract and salivary fistula result. Dr. Black states 1 that the 
cases of abscess opening beneath the malar bone are usually of the acute 
variety. As a rule, however, cases which exhibit the pus exit at a dis- 
tance from the seat of abscess are of the chronic variety. 

The acute and chronic cases differ as to their clinical histories. 

1 American System of Dentistry, vol. i. p. 940. 



CLINICAL HISTORY OF ACUTE ALVEOLAR ABSCESS. 485 



Clinical History of Acute Alveolar Abscess. 

Cases of apical pericementitis in which suppuration occurs usually 
present pronounced evidences of severe inflammatory action. The 
throbbing and tenderness, swelling and vascular engorgement are 
marked ; there may be, and usually is, more or less febrile disturb- 
ance with its attendant symptoms ; a full, bounding pulse, more or less 
oedema of the surrounding parts, the eye of the affected side may be 
injected, etc., as described in Chapter XVII. under the head of Acute 
Pericementitis. In from twenty-four to forty-eight hours a spot of 
fluctuation makes its appearance at the summit of the swelling, the spot 
becomes yellow and soon opens, affording escape to the abscess contents. 
As soon as the pus has discharged the inflammatory symptoms subside 
promptly and a persistent fistula remains, communicating with the 
abscess cavity. This comparatively benign course and termination is 
not universal. It is not at all uncommon to find cases which at the 
height of the inflammatory disturbance exhibit evidences of septic 
intoxication. The septic substances formed by the micro-organisms, 
and in other cases the organisms themselves, gain entrance to the lymph 
channels and are conveyed to the nearest lymphatic glands, producing 
evidences of inflammation in them ; swelling and pain of these glands 
are very common. Cases are recorded in which streptococci appear to 
have invaded the subcutaneous tissue, giving rise to marked phleg- 
monous inflammation. Dental literature contains the records of many 
cases indicating the occurrence of a pyemic condition consequent upon 
alveolar abscess ; organisms, by gaining entrance to the blood channels, 
forming septic emboli. 

The mild and less severe cases run the average course described. 
Many of them by finding early exit of the pus through the pulp canal 
of the affected root have comparatively light inflammatory disturbance ; 
in those cases in which the evacuation of the pus is delayed, or in 
which the opening occurs at points distant from the disease focus, the 
inflammatory action may be severe and prolonged. If the pus point 
toward the face, the skin, the subcutaneous tissues, and it may be the in- 
ternal periosteum also exhibit evidences of marked inflammation ; there 
is much swelling, the skin may become (Edematous, there is redness, 
heat, and throbbing pain. The external application of poultices by the 
patient, not at all an uncommon mode of domestic treatment, may 
aggravate the symptoms, soften the tissues, and induce the progress of 
the pus to the exterior. 

If in any of the cases which point in the mouth an undue swelling is 
formed at the height of prolonged inflammatory action, pus beneath the 
periosteum is to be feared, the pus stripping the softened membrane 



486 DENTO- ALVEOLAR ABSCESS. 

from the bone over a certain area. Should these cases not obtain quick 
relief by evacuation of the pus, necrosis of the denuded bone may occur 
(Fig. 469). Keattachment of the periosteum may take place even after 
extensive separation, provided the pus be evacuated early. 

Fig. 469. 




Necrosis of the buccal plate of the alveolar process from alveolar abscess (Black). 

Cachectic conditions exert a strong modifying influence upon the 
course and termination of alveolar abscess. In strumous or debilitated 
persons the disease tends to invade neighboring structures, whose resist- 
ance is lessened. This is well illustrated by a case of obstinate maxil- 
lary caries which destroyed the entire process of one side, the begin- 
ning of the disease being apical pericementitis of a lower bicuspid. 
The carious process became chronic soon after the extraction of the 
oifending tooth, and persisted until the death of the patient from 
tuberculosis. 

Alveolar abscess occurring in syphilitic patients is prone to involve 
the deep structures, and more or less necrosis is not an uncommon 
sequel. 

Clinical History of Chronic Alveolar Abscess. 

After the subsidence of the symptoms attendant upon the formation 
and discharge of acute abscess, there is rarely a spontaneous healing or 
filling of the abscess cavity and tract with healthy granulation tissue ; 
the development of organisms in the abscess cavity and pulp canal con- 
tinues and produces a continuance of the suppurative process, forming a 
chronic abscess. 

In other cases abscess may have developed without marked inflam- 
matory symptoms, and yet a prolonged and obstinate pus formation 
occurs in the tissues of the apical region, the pus finding exit through 
the pulp canal, constituting what is known as blind abscess, one of the 
most common of the chronic types. 

Many of the cases which open upon the face are of the chronic 
variety ; during the development of the abscess and its discharge there 






DIAGNOSIS AND PRO GNOSIS. 487 

may be but little evidence of inflammatory action about the affected 
tooth. This is a common history of cases which have followed the 
death of a pulp through trauma, years before the discovery of the ab- 
scess. At some period a tooth receives a severe blow, and for some 
time is the seat of traumatic pericementitis, which subsides : it may be 
years after that a fistula is established in the mouth or upon the face, 
without a history of inflammatory disturbance. 

As pointed out by Dr. Black, the direction of pus-burrowing in 
chronic abscess is determined by gravity ; thus, if the abscess be upon 
a lower incisor the pus may burrow, opening beneath the chin, as shown 
in Figs. 467, 468. 

Sir John Tomes l has called attention to the tendency of pus to open 
at the angle of the jaw in abscesses affecting the lower third molars (see 
cases noted above). 

Diagnosis and Prognosis. 

Diagnosis. — If the pericementum of a pulpless and open tooth have 
been the seat of acute and marked apical inflammation of septic origin 
for a longer period than thirty-six hours pus is almost invariably 
formed, and alveolar abscess is present. The diagnostic symptoms are 
those of acute pericementitis described in Chapter XVII. In case any 
marked inflammatory disturbance is found about the maxillary region 
either within or without the mouth, examination of the teeth of the 
affected side should always be made, as a large percentage of such in- 
flammations are of dental origin. Any fistula existing in the maxillary 
regions, either within or without the mouth, is to be suspected as having 
origin in a septic pericementitis of some tooth. 

A soft silver probe is to be passed along the tract to determine its 
direction and, if possible, which tooth is affected. As a rule, such a 
tooth will itself exhibit objective evidences of abscess and the patient 
will give a history of subjective symptoms — those of inflammation of 
pericementum. 

Should the tooth indicated as the affected one be free from caries, 
the thermal test is to be applied to indicate the vitality or the necrosis 
of the pulp. Should the tooth not respond to applications of a pointed 
piece of ice, it is possible it may offer slight response to applications of 
heat. It is next examined by light reflected from the ordinary, or 
better, the electric mouth mirror, when, if the pulp be dead, opacity of 
the crown will be detected. 

An abscess upon an upper incisor opening upon the nasal floor may 
cause a discharge simulating that of ozena ; an examination of the nose 
will reveal a teat-like elevation upon the mucous membrane covering 

1 Dental Surgery. 



488 DENTO-ALVEOLAR ABSCESS. 

the nasal floor and an incisor beneath will be found carious and having 
a putrescent pulp, or, if non-carious, a history of traumatic pericemen- 
titis and a present opacity. 

It may be mentioned here in connection with death of the pulp from 
traumatism, that continued thread-biting, biting very hard substances 
such as pieces of ice, nuts, etc., may cause death of the organ, presum- 
ably by thrombosis. 

It is possible that the direction taken by the probe which is passed 
into the fistula will point away from the teeth present, passing into a 
space from which a tooth has been extracted. In that event the pres- 
ence of a root fragment, or piece of necrosed process, may be suspected. 1 
Should the neighboring teeth be excluded as causes of an inflammation, 
there should be no hesitation in making an exploratory incision down 
to the end of the probe which has been passed into the fistula. Cases 
of dentigerous cysts have been detected in this manner. This condition 
would, however, be suspected when there was an absence of a tooth or 
teeth from the arch, no evidence past or present of pericementitis in 
any of the teeth of the arch, and a cystic tumor present in the jaw, or it 
may be a fistula discharging upon the face after a history of maxillary 
periostitis. 

Caries or necrosis, although in many cases the result of septic apical 
pericementitis, may yet exhibit fistulse opening into the mouth, without 
evident connection with the teeth. As a rule, cases of necrosis exhibit 
marked and wide evidences of chronic inflammation of the tissues over- 
lying the dead or dying bone ; there are usually several fistulse dis- 
charging from it. 

Caries may have but a single fistula and simulate closely ordinary 
alveolar abscess. Diagnosis is made by passing an excavator through 
the fistula. Dead bone is readily detected by touch, it has a rotten feel ; 
in caries the instrument may be passed through the dead bone in various 
directions, and a characteristic dead sound is elicited by tapping upon it. 
Careful examination of the teeth must be made in all of these cases, to 
determine the condition of the pulp and pulp canals. 

In passing an instrument through a fistula to the apex of an ab- 
scessed root, where the disease action has been of long duration, it may 
be found that the apex of the root is denuded of pericementum, and 
roughened — that is, the apical cementum is necrotic ; foreign deposits 
may be detected occupying portions of the necrotic area. 

Prognosis. — There are several factors which enter into the prognosis 

of a tooth and its surroundings which are affected by alveolar abscess. 

First, the severity and character of the inflammatory action and septic 

invasion. In cases in which inflammatory action is localized and pre- 

1 See case — Dr. Black, American System of Dentistry, vol. i. 



TREATMENT. 489 

senting none or but little febrile disturbance the prognosis is, as a rule, 
favorable ; but a slight amount of tissue necrosis occurs. Should, on the 
other hand, the inflammatory action proceed with volcanic violence, it 
is possible that not only may the pericementum suffer extensively, but a 
considerable portion of the periosteum over the process may be raised 
from the bone during the escape of the pus. Should this separation of 
periosteum be maintained for more than a few hours, the underlying 
bone may suffer to the extent of necrosis. In case of marked lymphatic 
involvement, the neighboring glands being swollen and tender, or even 
the skin over them exhibiting evidences of glandular inflammation 
beneath, more or less septic intoxication will probably occur, and un- 
less the focus of infection be promptly sterilized, septicemia is to be 
feared. 

Should evidences of diffuse cellulitis occur, indicating the invasion 
of streptococci into the adjacent soft tissues, it is a danger signal of 
threatening pyemia. 1 Heath 2 records a case of oedema of the glottis due 
to the involvement of the connective tissues about the glottis in the 
oedema accompanying a developing abscess upon a lower molar. 

The prognosis is good in a vast majority percentage of cases, when 
the offending tooth is extracted early in the attack, or at its height ; 
this applies even with apparently very grave cases ; still the prognosis 
as to the retention of the affected tooth is also very good, unless the 
abscess run a phagedenic course. In many of the cases of chronic 
abscess having a distant discharge the abscess may be cured and the 
tooth retained. Other cases obstinately refuse to heal so long as the 
offending tooth is present. 

Treatment. 

Treatment of Acute Abscess. — The general principles of treat- 
ment of alveolar abscess are those for the treatment of abscess in any 
part ; the details are of course modified in accordance with the anatom- 
ical peculiarities of the part to be acted upon. These principles are 
the removal of all dead matter, together with the active causes of the 
inflammation and suppuration, i. e. micro-organisms and their products, 
and the induction of a tissue regeneration which shall serve to restore 
parts lost through the formation of the abscess. The therapeutic means 
applied are instrumental and medicinal. The instrumental are the 
instruments employed to gain access to the focus of disease action, and 
those applied in the mechanical removal of dead parts. The medicinal 
measures include the agents employed to wash out the abscess tract ; 
second, those applied to destroy the active causes of the suppuration ; 

1 See case — Dr. E. C. Kirk, Proc. Odontological Society of Pennsylvania, 1892. 

2 Injuries and Diseases of the Jaws, 3d ed. 



490 DENTO-ALVEOLAR ABSCESS. 

third, the remedies applied to induce new tissue growth ; and next, those 
employed to maintain asepsis until the healing process is complete. 

The great primary objects in the management of acute alveolar 
abscess are four : First, if the case be seen early, to use every endeavor 
to abort the inflammation, as described in Chapter XVII. Second, 
to limit as far as possible the extent of pus formation, hence tissue 
destruction ; third, the earliest possible evacuation of the pus which has 
formed ; fourth, the thorough sterilization of the abscess cavity and its 
walls. 

Cases when seen may be at any stage of the disease process from an 
incipient pericementitis to the establishment of a fistula. The treatment 
of the early cases is that of pericementitis. In all of these cases one fact 
is never to be forgotten : that the pulp canals are the centres of infec- 
tion, and the more quickly and thoroughly they are drenched with 
powerful antiseptics the more limited will be the inflammatory action 
both in degree and extent, and the more limited will be the pus forma- 
tion. Attempts are therefore made to enter and sterilize cavities pari 
passu with the antiphlogistic measures applied to abort or limit inflam- 
matory action. 

Treatment of Abscess without Fistula. — Abscess has been de- 
scribed by the older surgical pathologists as the process through which 
Nature rids herself of an irritant. This is in a measure true, but it is 
essentially a destructive and not a conservative process. Nature does 
rid herself of the irritant through suppuration ; but it is done at the 
expense of tissue loss, and the wise surgeon endeavors to remove the 
irritant and limit the destruction. After the inflammatory action has 
persisted at its height for twenty-four hours, pus is probably present 
in the tissues of the apical region ; if immediate exit be given to the pus 
' the inflammatory symptoms w T ill subside. If the tooth be not so sensi- 
tive as to preclude touch upon it, an endeavor is made, after washing 
the pulp chamber with powerful antiseptics, to pass a very fine Donald- 
son^ bristle through the apical foramen. In many cases this may be 
done ; the pus escaping through the canal, the inflammatory symptoms 
begin to subside. This is a case of acute blind abscess ; its treatment 
will be first discussed. 

The conditions existing are more or less remnants of pulp tissue 
undergoing putrefactive decomposition ; the contents of the dentinal 
tubules are also in process of dissolution. Beyond the apical foramen 
is a fibrous tissue containing bloodvessels and nerves, in the meshes of 
which tissue pus is forming. Beyond the spots of suppuration, the 
tissues, which are in small part fibrous but are mainly osseous, are the 
seat of inflammation. 

The pus evacuated, the parts tend to spontaneous recovery provided 



TREATMENT. 491 

the sources of irritation be removed. The first step in sterilization is 
the destruction of putrescent matter in the pulp canals. If the tooth 
be sore after evacuation of the pus through the apical foramen, the 
patient is directed to use repeatedly an antiseptic mouth-wash, 3 per 
cent, pyrozone or any of the solutions of hydrogen dioxid, and report 
in a few hours, when the broach is again passed through the apex of 
the root, the canal syringed out with hydrogen dioxid and dismissed for 
twenty-four hours, when the inflammatory symptoms will have so far 
subsided as to permit working upon the tooth. At this sitting, a slight 
flow of pus will still be found ; the canals are syringed, rubber dam 
applied, but never with a clamp on the. affected tooth. Sodium di- 
oxid either dry or in 50 per cent, solution is placed in the canals, and 
frequent re-applications made. At the expiration of about a half-hour 
the canals and abscess cavity are syringed out with an acid solution of 
hydrogen dioxid, and dried. The canals will now be sterilized and also 
the general abscess cavity. It is possible, however, and probable, that 
organisms may still occupy the deeper recesses of the tissue bounding 
the abscess cavity. The parts forming the abscess wall are of com- 
paratively low vitality and may not dispose of organisms present as 
would be done in more vascular tissues. It is the usual practice, there- 
fore, to apply to them a powerful antiseptic : campho-phenique, Dr. 
Black's 1, 2, 3 mixture, and lysol are all admirable agents in this par- 
ticular ; they are pumped into the abscess sac as well as possible, and 
the excess in the canals wiped away with wisps of cotton. 

There will be, immediately following this operation, a greater or 
less amount of exudation from the abscess walls, which diminishes as 
granulation proceeds about the apex of the root. The condition is one 
of granulating ulcer. An escape is provided for this exudation by 
leaving the dried canals unfilled for twenty-four hours, when a loose 
cotton dressing may be applied, hermetically sealing the cavity com- 
municating with the saliva after each dressing. In two days the dress- 
ing is removed, always sterilizing the tooth walls and isolating it when 
the cavity is to be opened. On the third day a larger dressing of 
cotton, dipped in campho-phenique and wrung out, may be applied. 
After two days, should the cotton exhibit little or no evidence of exuda- 
tion, a firmer dressing is applied, to remain about four days ; the next 
dressing remains a week, when the abscess cavity should be filled with 
tender granulations. Pending the organization of the granulation tissue 
there is probably no better canal filling than salol having a core of 
gutta-percha. It is unirritating and may be applied without causing 
irritation. Dilute solutions of formaldehyd have been found to be 
extremely useful in this class of cases as well as in all cases involving 
sterilization of the pulp canal. The high antiseptic value of formalde- 



492 DENTO-ALVEOLAR ABSCESS. 

hyd and its great penetrating power place it among the most satisfactory 
agents in the dental pharmacopoeia. For the treatment of root canals 
with apical pericementitis a wisp of cotton moistened with a 5 per 
cent, solution of formalin (the 40 per cent, solution of the gas in 
water) and sealed in the canal will in a few hours completely sterilize it, 
so that usually the canal may be permanently closed within twenty-four 
hours. Rarely, a second dressing is required. Stronger solutions of 
formalin are irritating and should be avoided, as they may cause 
necrosis if used beyond the strength stated, or even in that strength 
if used in too large quantity or too frequently. 

Should the effort to enter the apical region through the canal fail, and 
pus be present, an entrance should be effected through the gum. At a 
point on the gum immediately overlying the apex of the affected root, 
a pointed bistoury is quickly thrust down to the bone, the bleeding is 
encouraged by the use of hot water for several minutes, when a pellet 
of cotton which has been dipped into 95 per cent, carbolic acid is laid 
against the periosteum at the bottom of the cut. In a few seconds a 
spear drill driven by the engine is passed through the bone into the 
tissues of the apical region. Any bleeding which may occur is encour- 
aged as above mentioned. For washing the incisions and the abscess 
in such cases there is no agent more acceptable than a 20 per cent, solu- 
tion of phenol sodique, it being both sedative and antiseptic. A thread 
of floss silk dipped in carbolic acid is passed into the fistula to the seat 
of abscess, its projecting edge lying upon the gum ; this will prevent too 
rapid a healing of the fistula. The case now resembles an abscess with 
a fistulous opening, the next variety of acute alveolar abscess ; the treat- 
ment for both is the same. 

Treatment of Abscess •with Fistula. — Cases of acute alveolar 
abscess discharging through a fistulous opening are either seen when 
the pus has perforated the bone and is making its exit through the soft 
tissues, or in cases where the inflammatory symptoms run high, the 
usual methods of aborting the inflammation having failed, pus forms 
and the abscess discharges rapidly, it may be within thirty-six hours, 
The use of pepper plasters and like devices to induce pointing of an 
abscess are irrational ; they render no service which cannot be per- 
formed better and more expeditiously by an incision made down to 
the bone by means of a sharp bistoury. In all cases of acute apical 
pericementitis where the swelling of the gum is marked, an early and 
deep incision is useful and advisable. If pus be already formed and 
the abscess pointing, escape is afforded it ; if the pus have not yet per- 
forated the periosteum that structure receives early relief from a condi- 
tion which might threaten it. The greater the swelling the more 
imperative is the necessity for this incision, which must be freely made. 



TREATMENT. 



493 



Fig. 470. 



A sharp curved bistoury is held as a pen, its point directed always 
. toward the bone, and is passed boldly down to the bone immediately 
over the apex of the root. 

Inflammatory symptoms, as a rule, subside promptly as soon as exit 
is afforded the pus. As soon as the tooth may be operated upon, its 
canals are to be treated as virulently and deeply infected centres, opened 
freely and sterilized with the utmost thoroughness. The usual and 
satisfactory method of accomplishing this is by means of a 50 per cent, 
solution of sodium dioxid ; after which a stout syringe filled with 3 
per cent, pyrozone is to have its contents driven forcibly through the 
abscess tract, the application to be repeated until the peroxid comes 
away clear. A few drops of campho-phenique or Dr. Black's 1, 2, 3 
mixture are placed in the pulp canal by means of Flagg's dressing 
pliers. This may be drawn into the abscess sac along 
its tract, emerging at the fistulous opening, by a little 
device of Dr. T. M. Hunter. 1 One of the rubber cups 
used for finishing fillings and cleaning teeth is to have 
its tool opening filled with gutta-percha, the concavity 
of the cup moistened and pressed flat against the gum, 
covering the fistula ; removing the pressure from the 
centre of the cup but keeping its edges closely in con- 
tact with the gum, a suction is created drawing the 
medicament through the abscess tract. The writer has 
used these cups, but mounted on a No. 300 mandrel 
(Fig. 470), for this purpose for several years ; indeed 
the discovery that Dr. Hunter had employed and ad- 
vised it as a means of emptying abscess cavities was a 
gratifying surprise, as he states that they serve this 
purpose admirably. 

The sterilized canals are now to be thoroughly filled with cotton twists 
or gilling twine which has been moistened with the last-named antisep- 
tic, or 5 per cent, formalin, the crown cavity sealed, and the case dis- 
missed. In twenty-four hours, only a slight serous exudate should be 
pressed from the fistula. In a week the abscess cavity should be 
healed. In that time a permanent canal filling may be inserted, but it 
is wiser to defer the filling of the crown cavity for some time — that is, 
if it is to be filled with cohesive gold. 

In case of acute abscess w T here marked inflammatory symptoms with 
involvement of neighboring parts persists after the evacuation of the 
pus, the gum overlying the tooth being purplish and tumid, the tooth 
very loose, and no diminution of the attendant fever, neighboring 
structures in addition to the tooth are in danger, and the latter should 
1 Dental Cosmos, vol. xxxiv. p. 82. 




494 DENTO-ALVEOLAR ABSCESS. 

be extracted. An early and free incision will frequently avert this con- 
dition and necessity for extraction. 

Should the case when first seen exhibit marked evidences of involve- 
ment of the tissues of the face, a threatening of the abscess toward 
pointing on the face, prompt and active measures are necessary. As a 
rule in these cases the pernicious domestic practice of applying poultices 
to the face has been followed, and in consequence the tissues of the 
cheek are distended and softened, lessening the suffering but inducing 
the flow of pus along the line of softening. Compresses wet with lead- 
water and laudanum — 

Ify. Plumbi subacet., 3J ; 

Tr. opii, 3j ; 

Aqua?, Oj.— M. 

should be laid upon the face, and an incision made at the line of junc- 
tion of the cheek with the gum, down to the bone over the apex of 
the root. As a rule, in these cases the pus has found its way into the 
tissues of the cheek, but drains through the incision ; a cut must always 
be made away from, not toward the cheek, to avoid cutting the facial 
artery or any of its branches. Opening upon the face may be averted 
by this means, even when the pus is beneath the skin. The danger of 
inclusion of the duct of Steno should be borne in mind should the case 
be one of abscess upon an upper molar, and energetic measures pursued 
to prevent the establishment of that annoying trouble, salivary fistula. 

When fluctuation of the inflammatory tumor upon the face becomes 
evident, indicating that an external opening must be made, it is prefer- 
able that it be made with a sharp knife and not by suppuration. Scars 
left by abscesses discharging spontaneously are irregular and disfiguring, 
those following clean incision are but a line. A curved bistoury is used 
to transfix the summit of the swelling, the knife is then carried outward, 
making an incision about an inch long. In this as in all cases of abscess 
where pus is detected the indication is to give it immediate exit. 

It occasionally occurs that abscess may be found upon the lateral 
aspect of a tooth containing a vital pulp. The tooth is free from 
caries, and is perfectly translucent. The most usual situations of these 
abscesses are upon the labial faces of the anterior teeth and the buccal 
faces of the molars, between the gingival margin, which may be intact, 
and the apex of the root. As a rule the evacuation of the pus and 
dressing with antiseptics causes a speedy disappearance of the abscess. 
Left to themselves they discharge as a rule at the gum margin. They 
are a frequent associate of the condition graphically described by Dr. 
G. Y. Black as phagedenic pericementitis. Believers in the gouty 
origin of this disorder note their occurrence in gouty patients. 1 In 

1 Typical cases are recorded in Proe. Academy of Stomatology of Philadelphia, 1895. 



TREATMENT. 495 

these cases the abscess is attended by more or less destruction of the 
pericementum. Cases may be seen in which the abscess involves the 
tissues near the apex of the root, the pulp being vital ; its death, how- 
ever, will doubtless result from the invasion. 

Acute apical abscess may discharge at the margin of the gum, follow- 
ing the pericementum. These cases are to be treated as abscess with 
fistula. In some cases subsequent to the treatment of the abscess there 
appears to be a restoration of the pericementum lost in the formation of 
the fistula. In others a permanent loss of tissue results. This mode 
of discharge is common about dead roots which have been in the jaw 
crown less for a long period ; a resorption of alveolar process has 
occurred and the root is retained by fibrous tissue. The treatment in 
these cases is that accorded any and all roots which may not be made 
serviceable — extraction . 

Treatment of Chronic Abscess. — For purposes of treatment, 
chronic abscesses are divided into two classes : those discharging through 
the pulp canal, what are known as blind abscesses ; second, those dis- 
charging upon the gum, at the neck of the tooth or in fact at any point, 
through a fistula. 

The usual condition existent with the blind abscess, is a cavity 
which may have any volume, its diameters, however, rarely exceeding 
three-eighths of an inch ; this cavity is bounded upon all sides by a 
fibrous capsule, analogous to the indurated surroundings of an ulcer ; the 
wall represented by the cementum of the affected tooth may be devoid 
of fibrous tissue, the pericementum being necrotic. The pulp chamber 
is the centre of infection ; the abscess cavity is the habitat of bacteria, 
which cause the peptonization of the inflammatory exudate from the 
wall of circumvallation, and destroy the exudation corpuscles, thus 
producing a continued pus formation. The observation and statement 
of Dr. Black have been quoted above, wherein he states that gravity 
largely determines the direction pursued by the pus in chronic abscess. 
This tendency will be found to exist with the blind variety also. 

The tendency of long-continued pus formation about the roots of the 
upper teeth will be to progress along the pericementum, resulting in a 
molecular necrosis of that structure from the apex downward. The 
condition is represented in Fig. 471. The extent to which the apex of 
the root projects into a cavity increases with the progress of the necrotic 
process. 

In the lower teeth, the influence of gravity carries the suppurative 
process away from the apex of the root, the abscess cavity increasing 
downward (Fig. 472). 

If the case be seen shortly after the subsidence of the inflammatory 
attack which may have ushered in the suppurative process, the cavity 



496 



DEN TO- A L VEOLA E A BSCESS. 



may be very limited in size, only a trifling amount of the pericementum 
being destroyed. 

It is advisable in these cases, after thorough sterilization of the canals 
and dentin by means of sodium dioxid or formalin, to increase the size of 
the natural drainage-tube, by enlarging the pulp canal ; a fine Donaldson 



Fig. 471. 



Fig. 472. 





Chronic blind abscess of upper incisor, showing Chronic blind abscess upon lower tooth, 

tendency of pus to progressively destroy peri- showing tendency of pus to sink into 

cementum owing to the influence of gravity. the substance of the lower maxilla 

owing to the influence of gravity. 

cleanser should pass freely through the apical foramen. The abscess 
cavity is now forcibly and thoroughly syringed out with 3 per cent, 
pyrozone. It is advisable after effervescence ceases to mechanically 
withdraw, or aspirate, the contents of the abscess. This may be readily 
done by passing the point of a syringe into the canal, filling around it 
with gutta-percha and withdrawing the piston, when the contents of the 
abscess will flow into the syringe. Any instrument (syringe) employed 
for this purpose should soak for hours in an antiseptic before using it 
in other cases (a 20 per cent, solution of phenol sodique is an excellent 
sterilizing agent) ; the same syringe should never be used for any other 
purpose. A small amount of 25 per cent, pyrozone, ethereal, may now 
be placed in the canals and pumped into the abscess cavity ; then canals 
and sac are dried by means of warm blasts, and a wisp of cotton dipped 
in campho-phenique and wrung out is packed in the canal. The 
patient reports the day following, and if no discomfort be felt the tooth 
remains closed until the following day. If upon opening the tooth no 
evidence of exudation is seen, and no effervescence occurs upon applica- 
tion of 3 per cent, pyrozone, the drying and dressing are renewed, to 
remain about three days. If any evidence of pus be detected, the canals 
and abscess are syringed with weak pyrozone, and a small amount 



TREATMENT. 497 

of campho-phenique, Dr. Black's 1, 2, 3 mixture, or myrtol may be 
pumped into the abscess, and by repeated blowing of warm blasts driven 
into all parts of the cavity. In twenty-four hours a slight serous flow 
should be observed, but if after three days any evidence of pus be de- 
tected, it is the signal to establish an external fistula. This is done in 
the manner before described. The treatment is now the same as that 
for the next class : chronic abscesses having fistulous opening. 

Chronic Abscess with Fistulous Opening-. — In these cases the 
canals are opened and sterilized as in all others by the powerful anti- 
septics named. The abscess tract is syringed out with 3 per cent, pyro- 
zone until bubbling at the external orifice ceases. The canals are filled 
with campho-phenique, or the 1, 2, 3 mixture, after the dressing-pliers 
method, and drawn into and through the abscess cavity and tract by 
means of the rubber-cup device already mentioned. In cases in which 
the rubber-cup device fails to cause a flow of the medicament from the 
pulp chamber out through the fistulous tract, the result may be attained 
by filling the canals and pulp chamber with the fluid desired ; for 
example, campho-phenique or strong carbolic acid, and then placing 
over the cavity a pellet of unvulcanized caoutchouc or warmed and soft- 
ened gutta-percha base plate and exerting strong pressure upon it with 
a ball-end burnisher just enough smaller than the cavity to force the 
material well into the pulp chamber. This will cause the medicine to 
flow out at the fistulous opening, where in the case of carbolic acid its 
presence will be manifested by its coagulating effect upon the margins 
of the fistulous orifice. 

The canals are to be temporarily filled with cotton saturated with an 
antiseptic, and as a. rule the case proceeds rapidly to recovery. Fresh 
cleansing and dressing are indicated if all evidences of inflammatory 
action, seen in the gum color, are not absent in three days ; in a week 
the external fistula should be closed. 

If after a week the fistula remain open, discharging 
serum, a sterilized excavator is passed through the 
fistula and it may detect denudation and roughness of 
the apical cementum. After a root has been the seat 
of chronic apical abscess for a long period, not only 
may the apical pericementum be destroyed (Fig. 473), 
but the cementum itself may become saturated with 
the products of decomposition and invaded by septic Chroni( 
organisms. It is not uncommon to find deposits of ing denudation of 

■. ,. ., -, -, j , c, i apex of root (a to ft), 

calculi upon the denuded cementum. feucn an apex with deposits f cai- 
is the source of constant irritation ; it is a foreign culus u P° n cemen- 

• i turn. 

body, and is to be removed. 

The operation of removal is technically known as amputation of the 

32 




498 DENTO-ALVEOLAR ABSCESS. 

apex. The canal thoroughly sterilized is to be solidly filled with gutta- 
percha. A vertical incision is made which includes the fistula and 
exposes the process ; the opening through the process is enlarged, by 
sweeping around its borders a large dentate bur. The incision, open- 
ing and abscess cavity are now packed with cotton saturated with phenol 
sodique, until all bleeding ceases. 

The necrosed cementum is now exposed ; a small and extremely sharp 
fissure bur, driven rapidly, is laid against the distal wall of the root and 
a constant pressure upon the bur maintained until the dead part is ampu- 
tated. A sharp scaler may now be employed to round the edges of the 
root and make the cut surface smooth. 

The cavity is syringed with phenol sodique, to thoroughly remove 
all blood-clots — favorable breeding-grounds for organisms ; as a final 
measure the walls are touched with campho-phenique, and the edges of 
the incision brought together, using if necessary a stitch to unite the 
upper edges. In the abscess cavity iodoform or nosophen gauze is to 
be packed, and renewed in a couple of days. For a week the patient 
is directed to employ repeatedly a mouth- wash of 3 per cent, pyrozone. 
No attempt should be made to fill such a tooth with cohesive foil for 
several months. 

In some of the cases of anomalous root form, such as a sharp bend 
upon the upper end of the root, and which renders it impossible to 
gain access to the apex of the root even through the aid of sulfuric acid, 
it may be necessary to treat the abscess through the fistulous opening. 
The roots are sterilized and cleansed to as great a depth as possible by 
the aid of sulfuric acid and fine cleansers, and the endeavor made to 
force hydrogen dioxid through the apical foramen and out of the fistula 
by means of a syringe. The cavity of the crown is filled with pink 
gutta-percha, and through it the nozzle of a syringe filled with 3 per 
cent, pyrozone is thrust, well up the canal. The piston of the syringe 
is forced down ; it may be the solution will appear at the opening of 
the fistula, or it may be the solution will fail to penetrate the fora- 
men and its backward pressure will force the gutta-percha from posi- 
tion. In that event myrtol is placed in the canal, which is filled with 
thread holding the same material. Three per cent, pyrozone is injected 
into the abscess cavity through the fistula, until effervescence ceases. 
The nozzle of a minim syringe (Fig. 441). charged with campho- 
phenique or the 1, 2, 3 mixture is passed into the abscess sac, and a 
couple of drops deposited. In very many cases the abscess will then 
proceed to recovery. The treatment should be repeated if necessary. 
If several dressings applied at intervals of a week do not cause a 
disappearance of pus formation, amputation of the offending portion 
of the root will be necessary. An heroic method of treating chronic 



TREATMENT. 499 

abscesses which obstinately refuse to heal is by extraction and replanta- 
tion. The method applies alone to single-rooted teeth, although it has 
been successfully performed upon molars. 

The patient's mouth is to be sterilized, and the tooth extracted. It 
is immediately placed in a solution of 1 : 1000 mercuric chlorid at a 
temperature of 120° F. It has been repeatedly asserted, however, with- 
out satisfactory demonstration, that the cells of the deeper layer of the 
pericementum and the cementoblasts, and also the cement corpuscles 
retain their vitality for some period after extraction, and immediate 
replantation results in a re-establishment of the physiological union 
between the tooth and alveolus. It is certain that means and measures 
which are necessary to thoroughly sterilize the tooth before its reinser- 
tion would be fatal to any cellular vitality which might exist in the 
cement urn and its covering. 

The pulp caual is opened from its apex and cleaned out with canal 
cleansers, and pyrozone 25 per cent, placed in the canal, where it is al- 
lowed to remain for some time. In the meantime the socket from which 
the tooth has been removed is syringed out with pyrozone, and should 
the pericementum not be adherent to the tooth, the depth of the socket 
is scraped by means of large spoon excavators to remove the tissues 
implicated in the abscess. The cavity is washed out with pyrozone, 
and a pledget of cotton which has been dipped in campho-phenique is 
placed in the socket at its bottom. The tooth is dried by means of 
warm air ; the soft tissues, if any be present, at the apex are cut away 
for about one-eighth of an inch. The canal is filled with gutta-percha 
or solidly filled with gold, the end of the root cut off as far as it has 
been denuded of pericementum, smoothed, and returned to the antiseptic 
solution. The cotton is removed from the tooth socket, which is 
syringed out with 3 per cent, pyrozone, and the tooth returned to posi- 
tion. It is tied to the adjoining teeth by means of silk ligatures or held 
in place by an appropriate retaining appliance. 

Occasionally the seat of an alveolar abscess may be at the bifurca- 
tion of the roots of a molar. This may occur upon vital teeth owing 
to a foreign body being driven beneath the margin of the gums and into 
the point of bifurcation. In these cases it is noted that the inflamma- 
tion affects the gum about the neck of the tooth ; over the apices of the 
roots there may be no evidences of inflammation ; pus forms and dis- 
charges quickly. Syringing out the tract with 3 per cent, pyrozone 
usually frees it from pus and the offending substance — it may be a 
bristle of a toothbrush — and the case heals rapidly. 

Cases are seen in which the gum attachment about the neck of the 
tooth is unbroken ; and free access may be had to the apex of each 
root of a tooth manifestly suffering from acute pericementitis, pre- 



500 DENTO-ALVEOLAB ABSCESS. 

sumably due to a putrescent pulp. In a day or two a discharge of 
pus may be noted about the neck of the tooth. Such teeth when 
extracted exhibit an unmistakable abscess sac in the pericementum at 
the bifurcation of the roots. Whether the pyogenic organisms have 
traversed the dentin in the bottom of the pulp chamber and the 
cementum beneath, and thus inaugurated the suppurative process, is 
undetermined ; it may be, however, that waste products from this 
source following the channel named may have saturated the cementum 
with noxious material and caused the inflammation, or the organisms may 
have found entrance at the gum margin. The diagnosis of such a con- 
dition is most uncertain before pus finds exit at the gum margin. Such 
a case is to be treated by sodium dioxid, full strength, placed in the 
floor of the cavity, frequently washed away and renewed until the base 
of the pulp chamber is bleached lokite. The abscess cavity is syringed 
out with pyrozone. 

Another variety of abscess should receive mention : that occurring 
about lower third molars, affecting the gum tissues partially enclosing 
the emerging crown. The gum overlying and surrounding the erupting 
tooth becomes reddened, tumid, and exquisitely sensitive ; if the inflam- 
mation be not aborted by timely incision and antiseptic washes, pus may 
form, and the gum acquire an ulcerous appearance. The treatment is 
free incision, dividing the swollen gum, and syringing with 3 per cent, 
pyrozone. If there be ulcerous surfaces they are to be touched with 50 
per cent, solution of trichloracetic acid. 

Occasionally the muscles of mastication may become affected by the 
inflammatory process, and inability to open the jaws result. Such cases 
are not uncommon when the eruption of the tooth is delayed by lack of 
room between the ramus of the jaw and the second molar. The extrac- 
tion of this latter tooth may be required before relief is secured. 

Complications of Alveolar Abscess. 

The complications of alveolar abscess are due in acute cases to the 
involvement of other tissues than those commonly affected in the course 
of abscess formation and discharge. They depend in great part upon 
peculiarities of the anatomical relations existing between teeth and their 
surroundings, and, as anatomical variations are not uncommon in these 
parts, aberrations of disease process may be found with unwelcome fre- 
quency. An examination of some of Dr. Cryer's sections 1 will exhibit 
in one case the root of a lower second bicuspid penetrating the passage- 
way for the inferior dental vessels and nerves. It is quite possible that 
an abscess upon such a tooth discharging about the fibrous sheaths of 

1 Proc. of American Dental Association, 1895. 



COMPLICATIONS OF ALVEOLAR ABSCESS. 501 

these vessels might travel to distant parts — backward through the in- 
ferior dental foramen, or forward through the mental foramen. 

The roots of molar teeth instead of having their thinnest bony cov- 
ering overlying their buccal aspects, may have their apices almost per- 
forating the lingual wall of the bone ; in others the apex of the root of 
a lower molar is found beneath the line of insertion of the mylo-hyoid 
muscle. Abscess from such a case as this would probably discharge not 
into the cavity of the mouth, but in the submaxillary triangle. (See 
the case of Dr. Cryer's noted early in the chapter.) Dr. Harrison 
Allen ] records one of these cases. The septic roots of a lower third 
molar were the exciting cause of pericementitis, followed by osteitis 
and maxillary periostitis. Pus found exit beneath the mylo-hyoid 
muscle and gravitated, forming a collection about the hyoid bone, and 
from that point passed upward upon the face in the line of the facial 
artery. The abscess in addition pressed directly upward against the 
floor of the mouth and caused unilateral glossitis, from the mechanical 
effects of which upon the organs of respiration the patient died. The 
duration of the extra -maxillary complication was but four days. 

In the progressive resorption of the inner substance of the superior 
maxillary bone which results in the formation of the maxillary sinus, a 
process which certainly continues longer in some persons than in others, 
the bony structures may be removed to such an extent that but a thin 
layer of bone, periosteum and mucous membrane covers the apices of 
the roots of molars. Dr. Cryer's sections exhibit two cases in which 
the excavation of the sinus has proceeded down between the roots of an 
upper molar, creating such a condition that abscess upon either palatal 
or buccal roots must almost inevitably discharge into the sinus. No 
doubt many cases of incipient empyema of the antrum are aborted by 
the early extraction of abscessed molars, the antral complication being 
unrecognized. It is presumable that most of the cases of empyema of 
the antrum afford subjective evidence comparatively early, owing to the 
lighting up of inflammation and purulent catarrh. 

The student is advised, in studying the relations of the teeth with the 
maxillary sinus, to a careful and repeated reference to the sections of 
Dr. Cryer. He calls attention to a fact frequently overlooked and un- 
taught, that the orifice or opening connecting the maxillary sinus with 
the nasal passage is near the roof of the former, so that while the patient 
is in the erect position collections of fluid must nearly fill the sinus 
before there is a discharge. In the recumbent position, however, the 
fluid escapes and may be found in the nostril of one side. This is 
symptomatic of antral empyema. In acute cases of the antral disease 
there is much swelling, oedema about the eyelid, etc. ; sharp lancinating 
1 Garretson's Oral Surgery, 6th edition. 



502 DENTO-ALVEOLAR ABSCESS. 

pains dart about the jaw. In the chronic cases, large accumulations of 
pus may occur and not be detected until the bone is thin and bulged, 
emitting a crackling sound upon pressure. Extraction of the offending 
tooth furnishes an outlet for the pus. 

It is usual to attempt the passage of an instrument through the 
pulp canals into the antrum and endeavor to preserve the tooth. Such 
a drainage is insufficient ; the wall of the antrum should be perforated. 
This little operation is readily done : At a point about one-eighth of an 
inch or more above the apices of the roots of the molars an incision is 
made through the mucous membrane of the buccal alveolar wall, clear 
to the bone ; a spear-pointed drill, a large one driven rapidly by the 
engine, is passed instantly through the outer antral wall. The drill 
is directed upward and inward. The opening is made sufficiently large 
to permit free irrigation. Into the opening thus made the point of a 
syringe, perforated to sprinkle, is placed, and the cavity washed out 
with 3 per cent, pyrozone which has been diluted one-half and made 
faintly alkaline by the addition of sodium dioxid. As pointed out by 
Dr. W. H. Atkinson many years ago, unless the irrigating fluid be 
made faintly alkaline it is irritating. As a stimulant injection to fol- 
low, LugoPs solution (liquor iodi compositus, gtt. xx to the ounce) is 
excellent. The canal of the tooth is to be thoroughly sterilized and 
filled. 

In the treatment of other complications, if the case be acute, the im- 
mediate extraction of the offending tooth and the free use of antiseptic 
mouth-washes will usually effect a cure. In the treatment of chronic 
cases, if the focus of infection, the pulp canals, be made antiseptic and 
the medicinal agents can be introduced into the abscess tract through- 
out, surprising cures may result, as the literature of dentistry testifies. 

Abscess upon Temporary Teeth. — Among the most trying classes 
of cases with which the dental operator is confronted are those of peri- 
cemental disturbance affecting the temporary teeth. The operator is 
torn by conflicting emotions : the desire to afford quick relief to the little 
sufferers and the hesitancy or dread of inflicting the amount of suffering 
necessary to relieve the acute pain. Fortunately the pain is relatively 
less than in adults ; the tissues being softer the child escapes the agoniz- 
ing pain attending the rapid formation of pus in the apical tissues of the 
adult. The swelling, redness, and febrile disturbance are usually greater 
in the child than in the adult ; pus forms more quickly and makes its 
appearance in the gum sooner. The principle of treatment is the same 
as with the adult — evacuation of the pus. The necessary incision may 
be made almost painlessly by employing a sharp-pointed bistoury hav- 
ing a razor-like edge. The child, reassured by a gentle examination 
and firm kindness, is directed to open the mouth and close the eyes, 



COMPLICATIONS OF ALVEOLAR ABSCESS. 503 

when the bistoury, held as a pen, is passed quickly into the swell- 
ing. 

The canals of temporary teeth are to be sterilized first with pyrozone, 
next with oil of cassia, and should be filled with " balsamo del deserto." 
Dr. W. H. White, to whom we are indebted for the introduction of this 
material, states that in roots of temporary teeth in which it has been 
placed the resorptive process is not interfered with. 

Abscess occurring upon temporary teeth should receive prompt at- 
tention and treatment to avoid possible injury to the permanent tooth 
beneath ; this, however, does not appear to be as frequent as might be 
supposed. There is a tendency in strumous children toward marked 
lymphatic involvement attending alveolar abscess ; and secondary 
abscess of the lymphatic glands is not uncommon. 

Chronic abscess in the cachectic individual which may not respond 
to the usual local measures of treatment may be materially benefited 
by constitutional treatment. This comprises regulation of the functions 
of the alimentary canal ; the use of such foods as beef peptonoids, mal- 
tose, etc. Iron and arsenic are administered when the patient is, as is 
usually the case, anemic. More important than any medicinal thera- 
peutics is systematic exercise in the open air. Raising the bodily tone 
raises the recuperative power of the tissues, and hitherto resisting dis- 
ease may be conquered. 

Perforated Roots. — Perforation of the walls of a root canal expos- 
ing the pericementum occurs, as a rule, in consequence of two causes : 
first, the invasion of dental caries; second, the injudicious or unskilful 
use of the reamer employed in enlarging canals, or, it may be, burring 
through the walls in the forming of a socket for the reception of the 
post of an Artificial crown. 

The direct consequence of the perforation is inflammation of the 
pericementum, and the usual result is ulceration of that structure. The 
symptoms and their severity are, as a rule, governed by the situation of 
the perforation. If this be at the lower half (toward the crown) of the 
root, there is usually a proliferation of tissue which intrudes upon the 
pulp chamber. This hypertrophied tissue may increase in amount, a 
resorption of the edge portion of the process occur, and a fungous mass 
bearing a close resemblance to fungous pulp bulge into the pulp cham- 
ber. In fact, in many cases it is impossible to distinguish between 
the naked-eye appearance of fungous pulp and the condition under 
discussion. The growth fills the pulp chamber and obscures the per- 
foration ; it is in addition, in many cases, exquisitely tender. In either 
event, whether pulp or hypertrophied gum, it is necessary to remove 
the growth. 

A spray of ethyl chlorid directed against the mass is perhaps the 



504 DENTO-ALVEOLAR ABSCESS. 

most effective anesthetic ; in a few minutes a sharp fine-pointed lancet is 
passed around the growth as far as it can be, and the excised portion 
removed. An application of tannin will check the bleeding ; pledgets 
of cotton dipped in tr. iodin. are packed against the remainder of the 
growth and covered in with cotton and sandarac varnish for twenty- 
four hours. This dressing is renewed from day to day until, if it be a 
fungous gum, the margins of the perforation are plainly seen. The 
canal is cleansed, sterilized, dried, and filled with salol and gutta-percha, 
or with paraffin and gutta-percha, to about half its depth. The re- 
mainder of the canal and crown cavity are washed out with 25 per cent, 
pyrozone, and a dressing of temporary stopping applied, filling the per- 
foration and yet not exercising much pressure upon the soft tissues. In 
two days the temporary stopping is removed and the cavity is washed 
out with 3 per cent, pyrozone and dried. A piece of No. 60 gold is cut, 
larger than the aperture ; this is dipped in chloro-percha and laid over 
the perforation. A disk of gutta-percha larger than the piece of foil is 
warmed, laid upon the foil, and pressed against it, sealing it to the 
cavity walls. The remainder of the cavity is then filled with zinc phos- 
phate. 

In case the perforation should be nearer the apex of the root the dif- 
ficulty is greatly increased. Attempts at passing cleansers to the apical 
foramen usually result in pricking the pericementum at the perforation 
and a flow of blood follows, filling the canal. The cleansers are bent so 
that in passing them to the apex they press against the wall opposite 
the perforation ; the apical portion of the canal may be detected and 
cleansed after this manner in some cases. The temporary dressings in 
these canals should be one of the antiseptic oils, cassia or myrtol. A 
dressing of oil on cotton should remain a week, and no attempt at canal 
filling be made until all evidences of pericemental disturbance vanish. 
A fine cone of gutta-percha is passed, when practicable, into the canal 
beyond the perforation ; the remainder of the canal is filled with chloro- 
percha, and the silk points covered with gutta-percha. The canal at 
the proximal side of the perforation is filled with the solution, by means 
of the long dressing pliers, the gutta-percha-covered silk being carried 
gently in position while the general mass is fluid. Balsamo del deserto 
should apply well in these cases. The canal is filled, or partially filled, 
with the material, and a large gutta-percha point introduced. 



CHAPTER XIX. 
PYORRHEA ALVEOLARIS. 



By C. N. Peirce, D. D. S. 



Definition. — " Pyorrhea alveolaris " is a generic term which, strictly 
defined, means a flowing of pus from an alveolus. It describes merely 
a symptom which may be and usually is attendant upon a variety of 
disorders. The term is applied in clinical dentistry to a complexus of 
pathological conditions which more or less clearly indicate a specific 
disease. 

History. — That pyorrhea alveolaris is not a recent disease, or one 
due to modern constitutional states alone, is rendered evident from the 
examination of the skulls of ancient as well as modern races. The 
alveolar processes of many crania widely separated both in time and in 
locality exhibit marked impairment of structure which bears the closest 
resemblance to that presented by processes which were known to have 
been the result of pyorrhea during life. 

Recorded observations of this disorder date at least as far back as 
1746, when M. A. Fauchard described its essential clinical features, but 
failed to designate it by any specific term. Following this, communica- 
tions describing the disease were published by Jourdain in 1778, by 
Toirac in 1823, and by M. Marechal de Calvi in 1860, in which it was 
described as a " conjoint suppuration of the gums and alveoli," pyorrhea 
inter-alveolo-dentaire, and gingivitis expulsiva respectively. 

The most important contribution to the knowledge of the nature of 
the disease which had up to that date been made was by Dr. E. Magitot 
in 1867. In his paper he states that the disease is characterized by a 
slow but progressive inflammation destructive of the periosteal mem- 
brane and cementum, proceeding from the neck to the apex of the root 
and involving the loss of the teeth. From the exact seat of the lesion 
he designated the disease osteo-periostiti alveolo-dentaire. Soon after the 
appearance of the periosteal inflammation, it became complicated with 
diseases of the gums and the osseous walls of the alveolus, though 
these are never primarily the seat of inflammation. Magitot regarded 
the causes of the inflammation as very complex, and to be sought for 
not in the teeth and gums, but in certain conditions of the general nutri- 

505 



506 PYORRHEA ALVEOLARIS. 

tion. The gouty and rheumatic presented the disease most frequently, 
though its presence in those suffering from diabetes and albuminuria 
was extremely common. The deposition of tartar on the roots of the 
teeth, which might at first glance be regarded as playing an important 
part in the causation of the disease, Magitot considered as accidental 
and not to be looked upon as a causative agent. With reference to the 
efficacy of any treatment, however, he advised the removal of the tartar 
as an indispensable preliminary. The points of diagnosis differentiating 
between this condition and the former, that of gingivitis, however 
severe, were also clearly recognized and noted. 

Following Magitot' s able paper was one by Serran in 1880, in which 
the author took exception to certain of Magitot' s views, as well as to the 
term by which the latter proposed to designate the disease. He recog- 
nized, however, that the disease was most common in middle life and 
occurred principally among the gouty, the diabetic, and the albuminuric. 
He believed that the primary manifestation was a local congestion of 
the gums, followed by an exudation into the peridental membrane which 
destroyed its vitality and led to the formation of pus and all the other 
symptoms and pathological conditions characteristic of the disease. A 
commission composed of MM. Depres, Delens, and Magitot was ap- 
pointed by the Societe de Chirurgie to consider the statements of Dr. 
Serran. In this report 1 they denied the gingival origin of the dis- 
ease, and stated their belief that the periosteal membrane and the 
cementum were the primary anatomical seat of the lesion ; that the 
succession of morbid phenomena completely precluded the idea of an 
initial gingivitis ; that the disease begins without any trace of conges- 
tion of the gums ; that after its formation the pus burrows toward the 
gingival border, which it detaches — without, however, for a time de- 
stroying its normal aspect ; that only after considerable augmentation 
of the flow of pus and the loosening of the teeth do the gums become 
implicated ; that the disease has nothing in common with the hypothesis 
of a gingival malady, and that it is most frequently a manifestation of 
a general state, or a diathesis. 

These were the views entertained and published by French surgeons 
on the nature of " pyorrhea alveolaris " about the period when the 
disease began to receive consideration from American dentists. Though 
pyorrhea alveolaris had long been recognized in the United States and 
various observations regarding its pathology and treatment had been 
published, it was not until Dr. John W. Riggs, in October, 1875, read 
a paper before the American Academy of Dental Surgery, entitled 
" Suppurative Inflammation of the Gums and Absorption of the Gums 
and Alveolar Processes/' that the disease began to attract the attention 

1 Bulletins et Memoires de la Societe de Chirurgie, tome vi. p. 411. 



HISTORY. 507 

its gravity merited. Notwithstanding the views entertained by Magitot 
and others regarding the constitutional character of the disease, Dr. 
Riggs in his communication l emphatically denied that the disease is an 
affection of the bone or of the gums, or that it is hereditary or constitu- 
tional, but, on the contrary, that it is the roughened teeth themselves, 
in consequence of the accretions from whatever source derived, which 
are the exciting cause of the inflammation ; that it is purely local in 
origin, the result of concretions near and under the free margins of the 
gums, the removal of which even in the third stage is followed by cure. 

In 1877 Dr. F. H. Rehwinkel 2 entered his protest against the 
theory of the local origin of the disease, and endeavored to prove that 
it not only may but does exist independently of foreign deposit and 
must depend on other than merely local causes, and that it is an 
hereditary and constitutional disease. 

Dr. L. C. Ingersoll, in 1881, published a paper entitled " San- 
guinary Calculus," 3 in which it was stated that the persistent flow and 
discharge of pus along the side of the tooth was caused by an inflamma- 
tion and ulceration at or near the apex of the root ; as a result of which 
molecular death the liquor sanguinis escaped from the bloodvessels into 
the surrounding tissues and became disorganized, the lime salts crystal- 
lized on the surface of the roots, and formed the deposit which from its 
origin he designated " sanguinary calculus." This deposition he re- 
garded as entirely distinct from salivary calculus, and as derived from 
the blood — the result of inflammatory action and not its cause. In 
other words, he held that pyorrhea is a local disease but beginning 
centrally ; that is, at or near the apex of the root. 

In 1882, Dr. A. Witzell read a paper before the German Society of 
Dentists, 4 in which it was asserted that the primary pathological change 
was an inflammation and caries of the alveolar border followed by a 
deposit just beneath the free margins of the gums, which became re- 
tracted and reverted. The entrance of micro-organisms into this carious 
region developed pus which became more or less infectious. In conse- 
quence he termed the disease " infectious alveolitis." He regarded the 
disease as a primary local alveolitis, having no constitutional relations 
whatever, a molecular necrosis of the alveoli or caries of the dental 
sockets produced by septic irritation of the medulla of the bone. 

In 1886, Dr. G. V. Black prepared for publication probably the 
most exhaustive paper in print in the United States, wherein pyorrhea 

1 Pennsylvania Journal of Dental Science, vol. iii. p. 99. 

2 Report of the Committee on Pathology and Surgery, Trans. American Dental Asso- 
ciation, 1877, p. 96. 

3 Ohio State Journal of Dental Science, vol. i. p. 189. 

4 Vierteljahresschrift filr Zahnheilkunde, 1882 ; British Journal of Dental Science, vol. xxv. 
p. 153. 



508 PYORRHEA ALVEOLARIS. 

alveolaris is treated as a local disturbance. 1 Calcic inflammation and 
phagedenic pericementitis are the terms he employs to indicate its cha- 
racter. Though he believes it to be wholly local, he thinks a serumal 
or sanguinary deposit may be closely allied with its origin. He de- 
scribes it as a destructive inflammation of the pericemental membrane, 
distinct from other inflammations of this tissue though having many 
features in common with them. The disease, he estimates, is essentially 
one of the peridental membrane rather than of the alveolus, though the 
destruction of these two structures is so nearly synchronous that it is 
difficult to say which has gone first. 

In 1886, Dr. W. J. Eeese read a paper before the Louisiana State 
Dental Association on " Uremia and Its Effect on the Teeth," 2 in which 
the chemical, physiological, and pathological relations of uric acid to the 
general nutrition were discussed. In this communication Dr. Reese ex- 
pressed the opinion that the inflammation of the pericemental membrane 
followed by suppuration and disorganization when in contact with the 
secretions of the mouth, is caused by the deposition of uric acid derived 
from the blood ; that the disease should be termed " phagedena peri- 
cementi ; " that " pyorrhea alveolaris " is a misnomer. He also stated 
that while the tophus on the roots of the teeth is the usual con- 
comitant of uric acid, it is not necessarily so, but that absorption of 
the pericemental membrane may take place without any deposit. 
Though a local treatment was advocated, he stated that without sys- 
temic or constitutional treatment the return of the trouble may be 
expected. 

Dr. John S. Marshall, in 1891, expressed his conviction that pyor- 
rhea has a constitutional origin and is closely allied to the rheumatic 
or gouty diathesis ; " that the deposition of the concretions upon the 
roots of the teeth in those localities not easily reached by the saliva, or 
in which the presence of the saliva would be an impossibility, is due 
to the causes which produce the chalky formations found in the joints 
and fibrous tissues of gouty and rheumatic individuals." 3 

The writer, in a series of papers published during 1 892-94-95/ pre- 
sented a number of clinical and pathological facts which in their totality 
it was believed established a kinship between pyorrhea alveolaris or 
hematogenic calcic pericementitis and the constitutional state familiarly 
known as the gouty or uric acid diathesis. 

Recent literature by American writers has dealt largely with the 

1 " Diseases of the Peridental Membrane having their Beginning at the Margin of 
the Gum," American System of Dentistry, vol. i. p. 953. 

2 Dental Cosmos, vol. xxv. p. 550. 

3 " The Rheumatic and Gouty Diathesis, with its Manifestations in the Peridental 
Membrane," Trans. American Medical Association, 1891. 

4 International Dental Journal, vols, xiii., xv. and xvi. 



TERMINOLOGY. 509 

problem of the etiology of the disease in question and has been princi- 
pally concerned in determining whether it is of constitutional origin or 
of local origin, or of both. Of the more important recent writings on 
the subject may be mentioned those of Drs. E. T. Darby, H. H. Bur- 
chard, G. V. Black, M. L. Rhein, E. C. Kirk, James Truman, Junius 
E. Cravens, Louis Jack, R. R. Andrews, and R. Ottolengui. 

Terminology. — No disease in the whole domain of surgery has 
received so many and such diverse names as the one under consideration. 
Each succeeding title was an attempt at the production of a comprehen- 
sive descriptive designation of the disease, but when it is recognized 
that the essential nature of the pathological processes involved is, even 
now, not fully made out, it is evident that the many names simply 
represent as many diverse views and can therefore have no permanency, 
nor do they, indeed, deserve any. 

The following is a fairly complete list of the synonyms of the dis- 
order : Suppuration conjointe ; Pyorrhea inter-alveolo-dentaire ; Gingi- 
vitis expulsiva ; Osteo-periostiti-alveolo-dentaire ; Pyorrhea alveolo ; 
Cemento-periostitis ; Infectioso-alveolitis ; Pyorrhea alveolaris ; Calcic 
inflammation ; Phagedenic pericementitis ; Riggs' disease ; Hemato- 
genic calcic pericementitis ; Blennorrhea alveolaris ; Gouty pericemen- 
titis. 

Examining the foregoing list, from the pathological point of view, it 
will be observed that there is a wide divergence of opinion as to the 
conditions which should be included under the generic title of pyorrhea 
alveolaris. 

As the term is now understood, pyorrhea alveolaris includes all of 
those cases of morbid action characterized by the following features : 
A molecular necrosis of the retentive structures of the teeth (their liga- 
ment, the pericementum), an atrophy of the alveolar walls, together 
with a chronic hyperemia of the gum tissue which leads to limited 
hypertrophy. After a variable period the teeth drop out, and the mor- 
bid action ceases with their loss. An examination of the roots of the 
teeth before or after their exfoliation usually exhibits deposits of cal- 
culi upon their surfaces. The disease is generally though not always 
attended by a flow of pus from the alveoli. 

Clinically the cases in which these phenomena are observed may be 
divided into two classes : First, those in which the disease process ap- 
pears to begin at the gum margin. The second class, those in connec- 
tion with which there is much controversy, begin at some portion of 
the alveolus between the unbroken and apparently healthy gum margin 
and the apex of the root, the pulp of the tooth being alive. These two 
conditions are so clearly differentiated from one another that each re- 
quires a separate description. Between these two classes, but intimately 



510 PYORRHEA ALVEOLARIS. 

associated with the latter, are to be included the cases described by Dr. 
G. V. Black l as " phagedenic pericementitis. " 



Class I. Pyorrhea Alveolaris beginning at the Gum 
Margin (Ptyalogenic Calcic Pericementitis). 

The first class — those cases beginning not at, but immediately be- 
neath the gum margin — are perhaps the most common, are by some 
erroneously supposed to be the only type of cases, and will require 
description first, as their causes, progress, prognosis, and treatment 
differ radically from those of the second class. 

Causes of Class I. — As in any disease, the causes of pyorrhea 
alveolaris grouped as Class I. may be divided into predisposing and 
exciting. The predisposing causes may all be included under the head 
of disorders causing a subacute inflammation of the gingivae. General 
catarrhal conditions; small but irritating deposits upon the necks of the 
teeth, as the accumulations upon the teeth of smokers ; fermenting 
deposits of food ; spirit-drinkers' stomatitis, mouth-breathers' gingivitis ; 
overcrowding of the teeth, mal-occlusion, and non-occlusion. The pre- 
disposing causes may also frequently be the exciting causes. The excit- 
ing causes proper are, however, subgingival scaly deposits of calculi. 

Clinical History. — In the mouth of a patient of one of the above- 
mentioned classes there will be noted at some period a gingivitis — a 
swelling of the gum which does not extend far from their margins. 
It is noteworthy that in these cases, as in the succeeding class, it is 
usual to find the disease attack teeth which are comparatively or quite 
exempt from the inroads of caries. Soon after the incipiency of the 
disease there may be squeezed from beneath the gum margins a detritus 
of food debris and inspissated mucus. At a later stage a sharp scaler 
passed beneath the gum margin may detach a flat greenish or black de- 
posit of calculus. Later, the gingivae are seen to become swollen and are 
gradually detached from the neck of the tooth, the flattened calculus in- 
creases in volume, and the irritation and injection of the gum deepens. 
" It is probable that these deposits have their origin in a reaction be- 
tween the altered mucous secretion of the gingival glands and the pro- 
ducts of lactic fermentation, their calcic salts being derived from the 
saliva." 2 The detachment of the gum does not become marked until 
these dark scaly deposits have encroached upon the margins of the 
alveolus. Soon thereafter, or indeed before, evidences of infection are 
observed, from the fact that pus may be pressed from the pockets. The 
disease progresses, the teeth loosen, and ultimately drop out or are re- 

1 A merican System of Dentistry, vol. i. 

2 H. H. Burchard, Dental Cosmos, October, 1895. 



PATHOLOGY AND MORBID ANATOMY. 



511 



Fig. 474. 



moved with the fingers, the injected gum remaining as a flabby mass 
and all evidences of dental disease ceasing with the loss of the teeth. 
The process may involve one, two, or more teeth and in some cases an 
entire denture. The origin of these deposits as well as those of ordi- 
nary calculi are so clearly traceable to the saliva that the writer has 
suggested for the conditions caused by them the name of ptyalogenic 
calcic pericementitis. 

Pathology and Morbid Anatomy. — The appended figure, semi- 
diagrammatic, will illustrate clearly the nature of the disease process 
(Fig. 474). It represents a longitudinal section through a tooth 
and its alveolus, with the vascular supply to the tissues. The peri- 
cementum and alveolar walls for some distance from the apex of 
the root are in a healthy condition. At the neck of the tooth are 
seen two deposits of calculi («, a). The overlying gum (6, b) is 
seen to be swollen and tumid at its edges. Immediately below the 
calculus, where it encroaches upon the pericementum, the latter tissue 
and also a portion of the alveolar periosteum is seen to have under- 
gone necrotic changes (d). The portion of alveolar wall uncovered 
by periosteum is in process of dissolution. In the pocket beneath the 
calculus a collection of pus is seen (c, c), so that the tissues beyond 
the calculus are involved in suppura- 
tive degeneration, which may be slow 
or rapid in its progress. 

The diagnosis is by sight and touch 
and not infrequently by odor, as par- 
ticularly in unhygienic mouths an offen- 
sive odor attends the progress of the 
disease. The gums are tumid ; from 
about the necks of the teeth pus may 
be pressed, and touch demonstrates the 
presence of flat, dark, and firmly ad- 
herent scaly calculi. 

The prognosis is favorable at even 
advanced stages, provided certain con- 
ditions may be obtained, viz. a removal 
or correction of the predisposing causes 
and a perfect removal of the exciting 
causes. 

Treatment. — The treatment is based 
purely upon the existing conditions, with two main objects in view. 
The first is to remove every source of irritation ; the second, to procure 
surgical rest until there is a return of the surrounding tissues to a 
normal condition. 




Ptyalogenic calcic pericementitis 
(Burchard). 



512 



PYORRHEA ALVEOLARIS. 




i': 







Cushing's scalers. 



As a general rule the first step of the operation consists in a careful 
and thorough scaling of the teeth. It is essential that the use of bulky 
scalers be avoided — first, for the reason that they rarely reach the 

deepest portions of the deposits ; 
second, that if they do, they cause 
more or less laceration of the gum, 
which should be kept as free from 
injury as possible. The instru- 
ments employed for this purpose 
by a majority of operators are the 
set known as Cushing's scalers 
(Fig. 475). Their mode of appli- 
cation and their position relative 
to the root are shown in Figs. 476, 
477. No instrument with a draw 
cut can remove these deposits with the same thoroughness as 
one operated with a push cut. With proper guarding it is 
improbable that these instruments should do harm to the 
vital parts beyond the calculus. Great care should be exer- 
cised in the use of pushing instruments to avoid forcing the 
dislodged particles into the deeper tissues. The scaling is a 
tedious operation, but one which should be persisted in until 
the root of the affected tooth is absolutely smooth. The scal- 
ing is alternated with a washing out of the pockets with 3 
per cent, pyrozone or hydrogen dioxid, which washes out the 
detached particles of calculus and disinfects the parts. " When 
the gums are tumid and interfere notably with the scaling pro- 
cess, applications are made of a solution of trichloracetic acid 
1 : 10 upon cotton tents ; this checks oozing, shrinks the gum, 

S giving a better view of the parts, and tends to soften the de- 

posits." l " It not infrequently happens that the teeth have 
suffered such extensive loss of their retaining structures that 
the operation of scaling tends to still further loosen them. In 
these cases the correction of mal-occlusion and splinting the 
teeth should be attended to before proceeding farther with the 
operation. The teeth should be ligatured to their fellows, 
and the excessive occlusion corrected by grinding away the 
points of contact with corundum wheels sufficiently to relieve 
the teeth of strain and to permit the fixing of a metallic splint 
by means of which the teeth may be held firmly, during and subsequent 
to the scaling operation." 2 

Splints for these cases are usually swaged metallic caps made of 
1 E. C. Kirk. 2 H. H. Burchard, International Dental Journal, August 1895. 



PATHOLOGY AND MORBID ANATOMY. 



513 



No. 31 metal, gold or silver, which are cemented to the teeth (Fig. 
478). When the teeth have suitable forms, a succession of rings sol- 
dered together may be employed ; in other cases the teeth are lashed 
together by means of fine gold wire. For temporary use No. 31 or 32 
annealed brass wire may be used, and when left in situ for weeks or 
months it exerts no deleterious effect. In fact, it appears to possess 

Fig. 476. 




Showing the manner of holding an instrument for detaching calcareous deposits when using the 
pushing motion. The third finger rests on the edges of the teeth, allowing freedom of the 
hand to make rapid and effectual movements in dislodging the calculi. 



antiseptic properties similar to those attributed to copper amalgam 
when used as a filling material. Or, if frequently renewed, floss silk 
may be used. Devices for this purpose are as numerous as designs 
for bridge work. 

Each root is to be perfectly scaled before proceeding to a second 
tooth. At the completion of the scaling the pockets are freely syringed 
out with pyrozone 3 per cent., and an application of an astringent made: 
a 10 per cent, solution of zinc chlorid, 20 per cent, solution of zinc 

33 



514 



PYORRHEA ALVEOLARIS. 



iodid, or tr. iodin. U. S. P. diluted one-half with alcohol. Prepara- 
tions of aristol and the officinal tincture of iodin are also used, all of 

which subserve the desired end, to 
sterilize the parts and to constringe 
the dilated vessels of the gum. An 
antiseptic and astringent mouth-wash 

Fig. 478. 





Showing the application of a thin flat 
instrument to the labial and approxi- 
mal surfaces of an upper bicuspid 
(pushing motion). 



is prescribed which the patient is to 
use several times daily. The follow- 
ing preparation applied on a small roll 
or tuft of cotton wool or by means of 



a soft toothbrush admirably meets the conditions : 



1^. Zinci ohlorid., cryst., 
Aquse menthse pip., 
S. Apply locally to the gums. 



3js; 
fgiv.— M. 



As early in the treatment as possible a thorough examination should 
be made with a delicate exploring instrument, so that any calculi which 
may be detected may be removed. 

A method of treatment which has given much satisfaction to the 
writer is as follows : First thoroughly cleanse the mouth and each 
particular pocket with hydrogen peroxid, electrozone, or some other 
equally efficient antiseptic. Then with a blunt but flexible broach, 
gold or steel, let each pocket from which pus has been issuing be very 
carefully saturated with trichloracetic acid ; this is repeated each visit 
if pas continues to flow. Following this, the pockets and gingival 
borders or margins are thoroughly treated with tincture of iodin, fol- 
lowed with solution of hydronaphthol and alcohol. If the gingivse, 
however, should be tumefied, an application of carbolic acid will prove 
advantageous : 

1^. Hydronaphthol, 31J ; 

Alcohol, £iv. 



This must be used with caution, for it is of sufficient strength to give 
the patient much discomfort if brought in contact with lips and tongue. 
The frequency of the visits and applications must depend upon the viru- 



GOUTY PERICEMENTITIS. 515 

lence of the disease. A wash for the patient's daily use made from the 
following formula will be of great service : 

1^. Hydronaphthol, gr. x; 

Glycerol, 3j ; 

Alcohol, ,lij ; 

Aquse dest., 3ij. 

The use of hydronaphthol in pyorrhea alveolaris was suggested by 
Prof. James Truman. 

The loss of alveolar w T alls is permanent ; the utmost the operator 
can hope in extreme cases is a reorganization of the tissues which 
have been softened as a consequence of the inflammatory action. 

Class II. Pyorrhea Alveolaris of Constitutional Origin — 
Gouty Pericementitis. 

The second class of pyorrhea cases — those in which local therapeusis 
has not been attended with permanent good results — are usually chronic, 
extending over a variable period of time, owing to the fact that they are 
but the local expression of constitutional states. Of these many forms of 
pyorrhea, one is particularly persistent, terminating only, unless prop- 
erly treated, with the exfoliation of the aifected teeth. This particular 
form, which has been the subject of much discussion during the past 
twenty-five years, the writer believes to have been shown to be but a 
local expression of the gouty diathesis and directly dependent on the 
deposition of the uric acid, urates, and calcium salts in the pericemental 
membrane ; though it is probable that allied and closely related com- 
pounds, such as the xanthin or alloxuric bases (xanthin, guanin, and aden- 
in), may also be present in small quantities. Indeed, as the gouty diathe- 
sis is largely dependent on a faulty metabolism of proteid compounds and 
an imperfect elimination of nitrogen-holding derivatives, it is quite pos- 
sible, though not proved, that any or all derivatives may be present in 
any pathological deposition. Inasmuch, however, as the amounts of 
these compounds are small, uric acid and uratic salts must be regarded 
as the chief of the specific irritants. As the origin of the salts is from 
the blood, the writer suggested the term hematogenic calcic pericementitis. 
Subsequently Dr. E. T. Darby suggested the happily applicable term 
gouty pericementitis. 

Clinical History. — It is noted that many patients who have mag- 
nificent dentures almost exempt from caries, at a period about middle 
life begin to have a loosening of the teeth which if unchecked leads 
to the loss of the entire denture. The disease may be observed at 
any stage from a slight loosening to impending exfoliation. An exam- 
ination of many cases will show that although they present apparently 



516 PYORRHEA ALVE0LARI8. 

diverse conditions, yet beneath these differences there is a striking uni- 
formity, particularly as to the family history of such patients. 

A complete and accurate study of the succession of symptoms which 
a typical case of gouty pericementitis presents from its inception to its 
termination. is rendered difficult, owing to the lack of extended observa- 
tion of the disease throughout the entire period of its evolution and dis- 
solution. This is especially true of this disease in its earlier stages. 
Nevertheless from an attentive study of a large number of individual 
cases in various stages of development it is believed that a fairly cor- 
rect picture can be deduced. 

First as to the teeth themselves ; as stated, they are almost exempt 
from recent caries. The teeth frequently exhibit a tendency to me- 
chanical abrasion upon their cutting edges or labial surfaces. If the 
patient be of a sanguine temperament, or this temperament combined 
with the bilious, the tendency to erosion is much more pronounced. 
It must be appreciated that this destruction of tooth tissue has nothing 
in common with ordinary dental decay or with the results of friction 
in mastication. 

In nearly all cases, should excavation of cavities in the teeth become 
necessary, or sections of lost teeth be examined, it will be found that the 
pulp has receded, i. e. has suffered a continued stimulation of its func- 
tional activity to the extent almost of obliteration. 

The patient may consult the operator as to the causes of repeated 
attacks of dental neuralgia, or the reason of consultation may be the 
alteration of position of one or more teeth. An examination of the 
organs, however, reveals no evident cause for either the neuralgia or the 
displacement. 

If the malposed tooth be kept under observation it will usually be 
seen to become elevated, loosen, and finally drop out. Other teeth 
become affected in a similar manner. Dr. Burchard has classified the 
course of pyorrhea as in three stages, as follows : " First, tooth indura- 
tion ; second, erosion or chemical solution of the crowns of the teeth ; 
third, a loss of the retaining structures of the teeth. Pathologically 
stated, there is first a stimulative stage; second, an irritative, charac- 
terized by altered secretion (erosion) ; third, the necrotic." 

The altered secretion pertains to the labial glands largely, and the 
necrosis to the pericemental membrane and the apical end of the root 
or that portion which has been denuded of the membrane ; while the 
alveolar process never, in the writer's judgment, undergoes any change 
except that of absorption and atrophy. 

By far the greater number of cases present themselves when the 
disease has made marked advance about one or several teeth and their 
immediate loss is threatened. 



GOUTY PERICEMENTITIS. 517 

Assuming that the gouty diathesis however well or poorly developed 
may be a predisposing cause, and the deposition of some characteristic 
specific gouty material from the blood into the pericemental tissues the 
immediate or exciting cause, we have an explanation for the irritation 
and necrosis of the alveolo-cemental membrane, which even in its early 
stages is easily recognizable. Coexistent with the pericemental hyper- 
emia there is more or less redness and turgescence of the gums, accom- 
panied by a sense of tenderness, soreness, and in many cases neuralgic 
pain, which latter symptom frequently precedes all other symptoms. 
In individuals already suffering from pyorrhea, the early irritative 
stage of the disorder may be frequently observed in teeth previously 
free from all signs of the disease. In nearly all such instances the focus 
of the diseased action is confined almost exclusively to the region toward 
the apical extremity of the root without there being the slightest evi- 
dence of peripheral local gingivitis. Too much stress cannot be placed 
on this fact, as it unquestionably marks the incipiency of the disease and 
is one of the early diagnostic symptoms. 

Somewhere near the apex of the root a distinct swelling occurs simu- 
lating an acute apical abscess. The tooth is sensitive upon percussion, 
but less so than when affected by purulent apical pericementitis ; more- 
over by isolating the tooth it is found to respond to applications of 
cold, proving that its pulp is alive. A bistoury passed into the swell- 
ing is followed by an escape of blood, and usually by a glairy purulent 
discharge also, although not always. In some cases a probe passed into 
the opening may show an absence of alveolar process at that point, and 
by a roughness reveal the presence of a deposit upon the root of the 
tooth. 

The teeth so affected usually present an appreciable elevation or 
protrusion from their alveoli in consequence of the enlarged or thick- 
ened and congested pericemental membrane. Should this congestion 
be permitted to continue, the inflammatory stage in consequence of the 
continued presence of the irritating deposit will supervene, with its con- 
comitant symptoms, heat, pain, swelling, and marked impairment and in 
some instances total arrest of the functions of the tissues involved. 

Inflammation once established will eventuate in localized suppura- 
tion with the abatement of the acute symptoms. The location of the 
suppurative process, if the case be seen and recognized early, will be 
found in the large majority of cases to be near the apical extremity of 
the root. As a rule, the pus takes the line of least resistance and bur- 
rows directly along the side of the root and opens externally at the 
gingival border. Occasionally the line of least resistance is toward 
the labial surface, with the discharge of pus on the gum opposite the 
end of the root, thereby establishing a fictitious opening simulating 



518 PYORRHEA ALVEOLARIS. 

the condition observed in an acute alveolar abscess ; these cases, how- 
ever, are very limited in number. 

Once established, these conditions of increased vascularity, tumefac- 
tion of the gums, and persistent discharge of pus may continue for 
months or years ; the rapidity with which the disease progresses and 
the extent to which the lesions develop will be directly dependent upon 
the state of the general nutrition and habits of the individual. 

As a result of the continued irritation induced by the deposit, the 
inflammation extends, the disturbed relation between blood and sur- 
rounding tissues increases, and the gums become flaccid, spongy, 
altered in color, and liable to hemorrhagic discharges. Associated with 
the congested and thickened condition of the pericemental membrane 
there is a gradual softening and absorption of the alveolar process, which 
may advance to such an extent as to almost or in some cases quite 
expose the root throughout its entire extent. The tooth thus freed from 
its retentive structures becomes loose, is freely movable in its enlarged 
and partially destroyed socket, is extremely liable to dislodgment by 
slight mechanical means, or if by care these are avoided it will within 
a limited time be exfoliated in consequence of the final and complete 
destruction of all its retaining structures. With this final result the 
progress of the disease is arrested. The alveolar socket being freely 
opened, the partially dead and decomposing tissues are removed and 
the remaining structures gradually restored to a normally healthy con- 
dition by the usual processes of repair. 

When once established, pyorrhea alveolaris does not confine itself 
to any one tooth, but may extend to adjoining teeth or make its appear- 
ance in rapid succession in widely separated regions of the mouth in 
the lower as well as the upper jaws until the whole denture becomes 
involved, with an eventual exfoliation of all the teeth and a complete 
resorption of the alveolar process. When these exfoliated teeth are 
examined there will be found at some point of the root surface, 
almost always near the apex, an incrustation of a dark, rough cal- 
culus, or it may be several of them, all minute. The origin of the 
deposits being clearly not from the saliva, which is the source of the 
calculi in the disease described under the head of Class I., it has been 
called serumal or sanguinary calculus (Ingersoll, Black) ; the writer has 
suggested as the name of the disease caused by such deposits, hemato- 
genic calcic pericementitis. 

These assumed gouty deposits led the writer into an investigation 
as to the family history of patients affected by this disease. Almost 
without exception these individuals have been shown to be either the 
victims of some phase or form of gout, of alleged rheumatism or of 
rheumatoid arthritis (rheumatic gout), or to have a clear family his- 



GOUTY PERICEMENTITIS. 519 

tory of one of these disorders. Careful investigation by several other 
observers has brought to light similar testimony, particularly within 
the past three years (Kirk, Darby, Burchard, Jack, and others). 

It had been noted by succeeding generations of practitioners that the 
therapeutic resources (local) of dentistry were insufficient to either check 
or cure the disease condition. All local means of treatment having 
been exhausted and shown to be of little or no avail, there was a natural 
inquiry into the exact nature of the predisposing and exciting causes of 
the malady, so that the therapeusis might be placed upon a rational basis. 

No purely local causes having been found sufficient to account for 
the dental condition, all constitutional states which were known to 
affect the teeth or their alveoli were examined and compared with the 
phenomena of the dental disorder. While it was and is found that 
several constitutional conditions do predispose to pyorrhea alveolaris, a 
flow of pus from a tooth socket, and most of these conditions may be 
included under the heading of diseases of sub-oxidation, none of them 
was found to cause a disease having the precise clinical phenomena 
noted in connection with the one under discussion. By a process of 
exclusion, and finally by direct clinical and experimental evidence, the 
field of inquiry was narrowed down to the conditions which clinical 
medicine has included under the heading of the disorders of the gouty 
diathesis. 

In order to clearly comprehend the connection of the general condi- 
tion with the local disease it is necessary to examine the essential, the 
intimate, nature of gout and its manifold manifestations. Much con- 
fusion has arisen in the discussion of this subject due to the lack of 
agreement of observers as to what constitutes gout, many apparently as- 
suming that gout is necessarily and inseparably connected with an acute 
attack affecting the metatarso-phalangeal articulation (the great toe). 

Pathology of the Constitutional Morbid Condition. — Pyorrhea 
alveolaris regarded as a local manifestation of the gouty diathesis is 
the result of a deposition of uratic salts in the pericemental mem- 
brane : these, acting as a local irritant, excite a specific inflammation ; 
while, as in other manifestations, the deposition of the gouty material 
is determined by an abnormal condition of the membrane, a condition 
of impaired vitality, the result of some mechanical or other irritation, 
which predisposes it to the infiltration. 

As no special manifestation of the gouty diathesis can be intelligently 
understood without reference to its constitutional relations, it will not be 
out of place to briefly consider the phenomena presented by — (1) The 
gouty diathesis as a constitutional malady ; (2) The special manifesta- 
tion here under consideration as a molecular necrosis of the perice- 
mental membrane, or pyorrhea alveolaris. 



520 PYORRHEA ALVEOLARIS. 

The gouty diathesis, in the general acceptation of the term, is a con- 
stitutional malady which manifests itself under a great variety of forms 
in different individuals. It is characterized by an excess of uric acid 
and its congeners in the blood, due either to increased production, 
through impaired or imperfect assimilation of nitrogenous food, or to 
imperfect elimination of the normal amount of urates by the kidneys. 
In either event there is a disturbance of the normal relations between 
uric acid production and the general nutritional process. The protean 
forms under which the diathesis manifests itself will vary in accord- 
ance with the type of constitution and with the peculiarities of organi- 
zation and the degree of vitality of individual organs and tissues. The 
lesions or pathological states observed are believed to be caused by the 
deposition into the tissues, from the blood, of urate of sodium. This 
diathesis is undeniably hereditary, as its presence is detectable in one 
form or another in fully 75 per cent, of all cases in two and even three 
generations. The diathesis can also be acquired by individuals who are 
subjected to the causes which rendered the diathesis hereditary. The 
age at which the local expressions manifest themselves lies between the 
thirty-fifth and fiftieth years, at a time when growth has ceased and the 
food supply is required only for tissue repair and heat production. It 
is most common among those who lead sedentary lives, who indulge in 
an excess of nitrogenous food beyond the capacity of the individual to 
perfectly oxidize, and those who consume excessive amounts of fer- 
mented and malted beverages and the heavier wines. 

The immediate cause of all gouty expressions appears to be the pres- 
ence of urates in the blood. The amount normally present is so slight 
that it is almost non-detectable by ordinary chemical methods. It was 
shown by Dr. Garrod that in gouty conditions the amount was increased 
tq as much as 0.175 per 1000 parts, and that this apparently small 
quantity was quite sufficient to act as the irritating cause of gout — a 
fact corroborated by other observers. 

The various theories which have been advocated from time to time 
in explanation of this uric acid increase in the blood plasma are unsatis- 
factory and contradictory ; whether it is the result of imperfect elimina- 
tion or of increased production through excess of nitrogenous foods it 
is difficult to state positively in the present state of pathology. It is 
quite probable that the diathesis is a neurosis which affects simultane- 
ously the assimilative as well as the excretory functions of the body. 
Whatever the explanation may be as to the accumulation of urates, 
their presence in the blood is generally admitted to be the immediate 
cause of any gouty manifestation. Dr. Dyce Duckworth states that " No 
conception of this malady is possible which should exclude from its 
purview the part played in it by uric acid ; " " The most unequivocal 



GOUTY PERICEMENTITIS. 521 

evidence of true gouty disease is that derived from the presence of 
uratic salts in the tissues." The immediate cause for the deposition of 
urates in individual tissues is to be sought for in a special vulnerability 
of the tissues, a loss of vitality, the result of mechanical, chemical, or 
vital influences. The views of Ebstein concerning the deposition of 
uratic salts have found general acceptance. He has apparently demon- 
strated that, in all connective tissues, previous to the deposition there is 
a primary necrosis of tissue elements without which the crystallization 
could not take place ; that this disturbance of tissue vitality is the 
predisposing factor and the crystallization the exciting factor of gouty 
changes. The blood plasma transuding through the walls of the capil- 
larv vessels carries with it urate of sodium in solution ; in the partially 
devitalized tissue inspissation occurs and in consequence crystallization. 

The urate of sodium as it accumulates acts as a specific irritant to 
the tissue, giving rise to a variety of phenomena in accordance with the 
character of the tissue involved. The gouty manifestations may be 
either acute or chronic. In the acute forms the signs and symptoms 
are those of an acute specific inflammation of a joint, usually that of the 
great toe. Clinical study of pyorrhea cases strongly indicates that the 
disease frequently attacks the dento-alveolar articulation before other 
articulations in point of time. The local symptoms, pain, heat, tume- 
faction are associated with marked constitutional reactions, disordered 
digestion, and numerous evidences of general disturbance of nutrition. 
The duration of the attack may be from a few days to several weeks. 
Repeated attacks lead to an impairment of the functions of the joint 
and a permanent alteration of its structure. 

In the chronic forms the symptoms are more widely distributed and 
their intensity is less pronounced according to the tissues involved. 
The various manifestations may be classified as follows : 

Articular gout, in which the deposit occurs in joints. 

Tegumentary gout, in which the deposit takes place in the skin and 
mucous membranes. Disease of the skin, such as eczema and psoriasis, 
and catarrhal affections of the mucous membranes, such as pharyngitis, 
chronic bronchitis, gastric and intestinal catarrhs, have long been 
recognized as expressions of gout. 

Visceral gout, in which the deposit occurs in the viscera, such as the 
lungs, heart, bloodvessels, spleen, liver, kidneys, i. e. giving rise to 
various diseased conditions or giving a peculiar cast to disease already 
established. 

Xervous gout, in which the nervous tissue is invaded, manifesting 
itself in a loss of mental energy, despondency, irritability of temper, 
headaches, neuralgia, etc. 

The limits of this chapter do not permit, nor is it desirable, to enter 



522 PYORRHEA ALVEOLARTS. 

upon a detailed statement of the symptoms or diagnostic features of 
these various phases of the gouty diathesis ; suffice it to say that, under 
one form or another, they are frequently present and associated with 
pyorrhea alveolaris. The pathology of pericemental inflammation from 
uratic deposition unfolds itself logically after a consideration of the 
diathesis in its constitutional aspects. Bearing in mind the fact that the 
alveolo-cemental membrane is a member of the connective-tissue group, it 
is not at all surprising that it also should become the seat of uratic deposits. 

Pathology of the Dental Disease. — Unfortunately the anatomical 
relations of the parts and other factors prevent the dental observer from 
collecting a complete and connected series of observations as to the exact 
pathology of the disease, so that our deductions in this direction are 
necessarily confined to a basis of clinical records. 

It is a natural inference that the pericementum is the part attacked 
because it is a point of minor resistance. The decreasing volume of 
pericementum which attends the progress of the disease in these cases 
is necessarily followed by a contraction of the caliber of the blood- 
vessels. It is not at all improbable that, as a consequence of the general 
physical condition, atheromatous changes occur in the pericemental 
bloodvessels leading to their occlusion. If it be necessary, as some 
pathologists maintain, that a death of cells precede the deposits in 
gout, this vascular change will account for the necrosis. The acid re- 
action of the necrotic area causes the deposition of urates, which are 
insoluble in acids. 

The deposit is the source of an irritation which in most cases is 
followed by inflammation, leading to inflammatory degeneration and 
probably coagulation necrosis of the cellular elements. The alveolar 
walls melt down particle by particle, the pericementum disappears, the 
diseased area usually becomes infected by pyogenic organisms, and the 
process of suppuration is an additional factor leading to the exfoliation 
of the teeth. As in necrotic areas of other parts, calcareous deposits 
occur, which cover and almost entirely obscure the primary deposit 
of urates. 

The condition following upon a deposit at the lateral aspect of a 
root, in its pericementum, is shown diagrammatically in Fig. 479. At a 
is seen the calculus embraced by a territory of inflammatory corpuscles, 
b. The pericementum which has so far escaped destruction is seen at c 
and d, that at d nourished by the anastomosing vessels from the alve- 
olar periosteum. At a later period this portion of pericementum be- 
comes involved in the degenerative process, and pus escapes at the neck 
of the tooth. In other cases the inflammatory degeneration extends 
from the deposit to the overlying gum, which is perforated. 

It is conceivable that such tissue changes should exist in consequence 



G UTY PERICEMENTITIS. 



523 



of injuries sustained during ordinary dental manipulations, the careless 
use of the teeth in biting unyielding substances, or even in the unwise 
use of toothpicks, brushes, etc. This supposition granted — and of its 
truth there appears to be much evidence, for the disease not unfrequently 



Fig. 479. 




Hematogenic calcic pericementitis (Burchard). 

develops after the operation of wedging, malleting, etc. — it is reasonable 
to believe that during the transudation of lymph through the lymph 
channels of the membrane, cementum, and dentin freighted with uratic 
salts, deposition and crystallization would readily take place in the 
dento-alveolar articulation as in other localities of the body. Not 
unfrequently has the writer recognized pus-exuding pockets resulting 
solely from wedging or long-continued malleting, and these in teeth that 
previously to the operation were as free from any appearance of either 
of these conditions as a normal tooth could be, yet an idiosyncrasy 
or predisposition existed — the exciting cause only being needed to 
develop it. 

With this deposit and accumulations between two unyielding bony 
surfaces and the pressure on the tissue elements in consequence, these 
salts will act as specific irritants and engender the well-known phe- 
nomena — pain, congestion, swelling, exudation, impaired nutrition, 
tissue disorganization, the formation of pus, an osteomyelitis resulting 
in the absorption of the alveolar process, and finally the exfoliation 
of the teeth characteristic of pyorrhea alveolaris. The most general 
seat for the deposition of these salts is toward the apex of the root, 
where the texture of the alveolo-cemental membrane is less firm and 
compact, and more bulky. 



524 PYORRHEA ALVKOLARIS. 

The supposition that pyorrhea alveolaris is a local expression of the 
general diathesis has been converted into an actuality by the demonstra- 
tion of the presence of uric acid and its allied salts in the incrustation 
found on the roots of the exfoliated teeth. The chemical analyses made 
by Prof. Ernest Congdon of the Drexel Institute have demonstrated 
the presence of these salts beyond question. 1 All of the established 
tests for uric acid were employed and in all instances crystals of uric 
acid, sodium urate, and calcium phosphate were detected. In several 
instances sodium urates were most abundant. The constant presence 
of these salts on the surfaces of the roots — the presence of which is 
ascertained by proper analyses and aided vision — taken in connection 
with the fact of the coexistence of gouty disorders in other tissues justi- 
fies the belief that the form of pyorrhea alveolaris here described is a 
gouty inflammation. 

The derivation of the salts from the blood, the abundance of the 
calcium salts present, and the primary location of the inflammatory pro- 
cess suggested to the writer the term hematogenic calcic pericementitis, 
though it is admitted that the single epithet gouty pericementitis would 
be sufficiently explanatory and descriptive. The succession of patho- 
logical states is readily explained and justified by the uratic deposit. 
The formation of pus is preceded by a lowering of the vitality and solu- 
tion of the pericemental tissues. This having been accomplished, the 
disintegrating peridental membrane affords a favorable nidus for the 
entrance and development of micro-organisms, which can be effected 
either by the route of the circulation or by lesions around the gum 
margins which give opportunity for direct infection from the oral fluids. 

When organisms once gain access to the devitalized tissue they mul- 
tiply with great rapidity, and in so doing increase the disintegration and 
solution of the pericemental membrane with the formation of pus. The 
specific bacteria which have been demonstrated to be present in the pus 
are the usual forms — the staphylococcus pyogenes aureus, citreus, and 
albus — which though capable of producing pus are not pathogenic in the 
sense that they are the causative agents of the pericementitis with the 
formation of an abscess. The purulent fluid burrows in the line of 
least resistance, which in the majority of cases is toward the gum mar- 
gin, whence it is discharged into the mouth, the fistulous tract thus 
established constituting the well-known pyorrheal pocket. 

By the continued irritation of the uratic deposition and the co-opera- 
tion of micro-organisms, the inflammatory process extends until the 
membrane is destroyed to such an extent that it is no longer capable 
of nourishing and supporting the teeth. 

The absorption of the alveolar process is in accordance with the laws 

1 See International Dental Journal, 1894, vol. xv. p. 1. 



GOUTY PERICEMENTITIS. 525 

governing bone softening and absorption in general. Any constant 
pressure, whether from inflammatory exudation, from tumors, or from 
mechanical or infective agencies which interfere with its nutrition, will 
lead to softening and absorption. In pericementitis the effusion exerts 
a pressure in both directions, toward the cementum and toward the 
alveolar walls ; as the latter are spongy in character, they readily yield 
to the absorptive process. Should the pressure continue indefinitely, 
or until the alveolar walls become denuded, caries or necrosis would 
inevitably result. Fortunately this termination is seldom if ever seen : 
the most careful examination of the alveolar process of a large number 
of patients has failed to show any alveolar denudation ; never, in the 
writer's experience, has there been either caries, necrosis, exfoliation, 
or sequestration of bone. Nor could there be, for the reason that the 
teeth are removed either naturally or artificially before complete de- 
struction of the pericemental membrane has been accomplished. With 
the removal of the teeth and its associated irritants the process of re- 
pair at once begins. The dead and dying tissues are removed, and 
fibrous tissues make their appearance, organization is established, and 
in a short time all traces of abnormal action have disappeared. 

Diagnosis. — The diagnosis of pyorrhea alveolaris becomes compara- 
tively easy when its constitutional relations, its mode of origin, its prin- 
cipal symptoms and pathology are borne in mind. The only diseases 
with which it might be (indeed, has been) confounded are, first, that form 
of pericementitis which has been designated a ptyalogenic calcic peri- 
cementitis ; or, second, a general gingivitis due to some systemic dis- 
turbance such as results from mercurial ptyalism or syphilis ; or, third, 
a severe inflammation of continuity due to some local disturbance such 
as an ill-fitting partial denture or an impacted tooth, possibly a third 
molar, greatly aggravated by some morbid systemic condition. These 
forms of pericementitis, however, present many points of contrast, dif- 
fering in their clinical history, their pathology, symptomatology and 
susceptibility to treatment. In the hematogenic forms the patient, in 
the great majority of cases, presents some other manifestations more or 
less pronounced, of the gouty or rheumatic diathesis. 

The age at which it makes its appearance is usually from thirty-five 
to fifty years. The extreme pain frequently present around the roots of 
one or more teeth in the early stages, and before there is any evidence of 
a gingivitis ; the deviation in the position, and the apparent or actual 
elevation of the tooth, with response to pressure ; the swelling or thick- 
ening of the pericemental membrane ; slight tumefaction of the gum 
with deep red or purplish color opposite the apical end of the root of 
the tooth or teeth affected — and all of this before the appearance of pus ; 
the isolated character of the inflammation, being usually confined to one 



526 PYORRHEA ALVEOLARIS. 

tooth or two or more teeth in widely separated regions of the mouth ; 
the exudation and discharge of pus along but one side of the root, 
detaching the gum at the neck, thus establishing a sinus or pus pocket ; 
the increase of the flow of pus from the interior of the alveolus under 
pressure ; the usually limited amount of calcic deposition as contrasted 
with the ptyalogenic form ; the destruction of the pericemental mem- 
brane and the denudation of the cementum ; the absorption of the 
alveolar process ; the loosening and exfoliation of the teeth indurated 
in structure and changed in physical appearance are the main charac- 
teristics of the disorder ; all these features taken in their totality so 
individualize this disease that there should be no difficulty in identi- 
fying it. 

In the ptyalogenic form almost the opposite conditions prevail. As 
a general rule there is no evidence that there is any constitutional diath- 
esis of which it might be an expression. The age at which it presents 
itself extends from the eighteenth year, sometimes earlier, to any period 
in later years, varying in its virulence with the varying systemic condi- 
tions and food habits of the individual. The presence of a calcic depo- 
sition around the neck of the tooth is often most abundant ; the primary 
gingivitis occasioned by the presence of this mechanical irritant is not 
confined to one tooth nor to isolated regions of the mouth ; the subse- 
quent extension (where neglected) and infiltration of this deposit into 
and beneath the pericemental membrane ; the localization of the sup- 
puration in the early stages around the margin of the gums ; the de- 
layed loosening of the teeth, the infrequent loss of the teeth and the 
susceptibility to successful treatment upon the removal of the salivary 
deposit : these features taken together fully characterize this disease and 
render its identification easy. 

Contrasting these different inflammatory states of the pericemental 
membrane from their inception to their termination, it becomes evident 
that distinct yet closely allied diseases are here very frequently confused 
and associated. 

Causation. — If we take as our point of departure the postulate that 
hematogenic calcic pyorrhea alveolaris is but a special manifestation of 
the gouty diathesis, we should expect to find in its causation the same 
predisposing and exciting agencies operative as in the production of all 
other manifestations of the general diathesis. 

Predisposing Causes. — 1. Heredity. — Among the predisposing 
causes may be mentioned heredity, which may be regarded as one of 
the most important factors concerned in its development. The writer 
feels justified in asserting, after a careful investigation into the family 
history of a large number of pyorrhea patients that fully 90 per cent, 
manifest an hereditary tendency to this disorder, parents and grand-par- 



GOUTY PERICEMENTITIS. 527 

ents having been victims of the same disease. Magitot was impressed 
with the significance of this fact years ago, and stated that pyorrhea 
extended through two and three generations and made its appearance 
at corresponding periods of life and in similar types of constitution. 

2. Sex. — As far as the writer's observations extend, sex does not 
appear to have much influence in the production of pyorrhea, women 
seeming to be equally affected Avith men ; eliminate the masculine 
dietary habit and there would certainly be little difference in the pre- 
disposition to the disease. 

3. Age. — The age at which pyorrhea most frequently presents itself 
is the period of middle life — that is, between the ages of thirty and 
fifty. It may be, though it is very rarely seen before the age of 
thirty, and still less frequently does it make its appearance after the 
age of sixty. These observations are corroborated by the writings of 
Magitot and others. It is very evident that pyorrhea is a disease 
belonging largely to a period of life when growth has ceased and food 
is required only for tissue repair and the production of heat. 

4. Diet. — A careful investigation into the dietary of pyorrhea 
patients will disclose the fact that there is usually a consumption of 
excessive quantity of both albuminous and starchy foods, much more 
than is necessary for the maintenance of the nutrition, and more than 
can be completely oxidized under the customary or existing modes of 
the individual's daily life. Coincidently there is also a diminished 
consumption of water, leading to an imperfect elimination and a reten- 
tion of the products of this incomplete oxidation. In connection with 
excessive consumption of food must be also mentioned as co-operative 
factors the use of fermented malt liquors, the richer claret wines, cham- 
pagnes, etc. While perhaps no one class of foods can be said to be 
especially active in the causation of pyorrhea it is evident that exces- 
sive quantity and variety, by impairing the activity of the digestive appa- 
ratus and giving rise to a large quantity of nitrogenized waste products 
through imperfect oxidation, would materially impair and lower the func- 
tional activity of the system generally and individual tissues in particular. 

5. Sedentary Occupations. — Occupation is also an important factor 
in the production of pyorrhea. In the majority of instances the disease 
makes its appearance in those who are obliged to lead lives of enforced 
inactivity — school teachers, accountants, etc. All sedentary occupations 
which necessitate insufficient personal exercise will favor the imperfect 
oxidation of food and at the same time retard the elimination of waste 
products. 

Exciting Causes. — The immediate agency in the development of 
pyorrhea is undoubtedly the deposition in the pericemental mem- 
brane of waste products of nitrogenous metabolism in combination 



528 PYORRHEA ALVEOLARIS. 

with calcium salts derived from the blood. This morbific material, play- 
ing the part of foreign bodies, irritates and excites the membrane to 
inflammatory activity and all its attendant symptoms. But even ad- 
mitting this deposition, there must be some predisposition on the part 
of the membrane which makes it specially liable to such deposition. 
This, it is believed, is in harmony with gouty deposition in all other 
tissues of the body ; it is to be found in impaired nutrition and lowered 
vitality in consequence of mechanical strain from an overcrowding of 
the dental arch, contusions or injuries consequent upon the usual and 
apparently unavoidable dental manipulations, such as wedging and 
malleting, and similar procedures. It may be from the unskilful em- 
ployment of toothpicks, toothbrushes, etc. — though these latter are rare 
as compared with other acts and conditions which may impair the nor- 
mal nutritional condition of the pericemental membrane. On numer- 
ous occasions where the predisposition existed, pyorrhea has devel- 
oped immediately following operations upon one or more teeth. Prof. 
Armand Depres 1 attributes considerable importance to the overcrowded 
condition of the dental arch as a predisposing cause in the develop- 
ment of pyorrhea. 

Treatment. — The treatment of gouty pericementitis resolves itself 
into both local and constitutional. 

The local treatment is to be directed toward removal of the deposit 
and the control and the suppression of the inflammation and its con- 
comitants, and has been already described at p. 511 in connection with 
the study of ptyalogenic calcic pericementitis. 

Constitutional Treatment. — Whatever the predisposing cause may be, 
the immediate or exciting cause must ever be borne in mind. This, it 
is believed, to a certain extent at least is found in all of those mechani- 
cal agencies, so well known to the dentist, which impair or lower the 
nutritional level of the pericementum, thus rendering it liable, under 
certain systemic conditions, to a deposition of uratic salts. The ques- 
tion has been raised as to why the membrane of one or more teeth 
widely separated or occupying positions on opposite sides of the mouth, 
either simultaneously or successively becomes the seat of inflammation 
when there is no continuity of structure. The answer to this must be 
found in the fact that impaired nutrition and lowered vitality in such 
structures are due in the majority of instances to mechanical injury of 
these. Malocclusion may be noted as a fruitful cause. It is certainly 
within the experience of many observant dentists that pyorrhea has not 
infrequently developed around a tooth after it has been subjected to the 
necessary mechanical manipulations incident to tooth protection and 
tooth preservation. 

1 Legons de Clinique chirurgicale, p. 9-656. 



GOUTY PERICEMENTITIS. 529 

This apparent interference with the nutrition of the pericemental 
membrane before the deposit of uric acid salts takes place is in accord- 
ance with what is believed to hold true for other manifestations of the 
gouty diathesis. As a prophylactic measure, therefore, it is suggested 
that whenever there is the slightest tendency to pyorrhea, or any other 
evidence of the gouty diathesis, great care should be exercised in all 
dental operations, so as not to impair the nutrition of the pericementum 
and thus establish the necessary condition for the uric acid deposit ; also 
correction of all cases of malocclusion — surgical rest as far as possible. 

The constitutional treatment which has been indicated as efficient in 
the elimination of already established uric acid conditions and the 
restoration of a faulty nutrition to its normal state may with great 
propriety be subdivided into hygienic and medicinal. 

The hygienic treatment embraces systematic outdoor exercise, stimu- 
lation of the functional activity of the excretory organs, the skin, bowels, 
and kidneys, and regulation of the diet, which must be insisted upon in 
all well-marked cases, and especially with those who, for various reasons, 
lead sedentary and inactive lives. Increased muscular activity quickens 
circulation, induces deeper and fuller respiratory movements, leads to 
greater vigor in the general nutritive processes ; waste products are 
removed more rapidly and the combustion of the food increased by the 
absorption of a large amount of oxygen. The promotion of the func- 
tional activity of the eliminating organs is well recognized as an import- 
ant hygienic measure. 

The perspiratory and sebaceous glands and the surface capillary circu- 
lation should all be stimulated by sponging of the skin with cold water, 
vigorous friction, and an occasional Turkish bath, where such treatment 
is not contraindicated by pulmonary or cardiac affections. Where the 
liver and intestinal glands are deficient in secretion with prevailing 
constipation, they should be stimulated into activity by the use of 
saline waters ; most excellent for this purpose being the Hunyadi Janos 
and Frieclrichshalle. These are especially to be commended because 
they contain a large percentage of sodium and magnesium sulfates, 
both of which are useful as eliminating agents. 

The kidneys should be assisted in the excretion of waste products 
by the free use of negative waters, or waters in which the saline con- 
stituents are present in minimum quantity. 

Hot or distilled water in sufficient quantity will flush the alimentary 
Ganal, increase the volume of blood, and stimulate the kidneys to 
increased activity. It is not only a common observation, but rather 
a remarkable fact, that gouty patients are inclined to drink but a com- 
paratively small quantity of water. One quart of hot water taken 
daily, in four doses, before breakfast, between meals, and at bedtime, is 

34 



530 PYORRHEA ALVEOLARIS. 

considered most beneficial in its effects in dissolving and removing irri- 
tating products. 

The most important of the hygienic measures in the treatment of 
all gouty manifestations is that pertaining to the diet. As uric acid is 
a liitrogenized compound and therefore presumably one of the imper- 
fectly oxidized products of albuminous or nitrogenized food, it is desir- 
able that such foods be excluded as far as possible from the daily 
diet. The value of this measure is admitted and insisted upon by all 
clinicians. 

In the milder manifestations of the gouty diathesis such as we 
assume exists in pyorrhea, it is not so imperative that all albuminous 
food be prohibited ; nevertheless, as many patients are consumers of 
large quantities of meat, it would be well to insist, if the effort to 
cure is to be made, upon the total exclusion of beef, veal, mutton, and 
pork, restricting the patient in albuminous diet to white meat of fowl, 
oysters, fish, and lobsters. Cheese, beans, and the white of eggs are 
considered objectionable, and in many cases of acute gout are strictly 
prohibited by the attending physician. 

Experience has shown that various alcoholic drinks, such as cham- 
pagnes, port, madeira, and sherry, are particularly liable to give rise to 
the accumulation of uric acid. The lighter wines, as claret and hock, 
are not considered so injurious. The malt liquors, beer, ale, and porter, 
are also by many clinicians considered in their influence to be great 
offenders. 

The medical and constitutional treatment, it is obvious, should be 
directed toward the elimination of uric acid and its compounds. For 
this purpose remedies which promote the formation of soluble and 
easily diffusible products which are readily eliminated by the kidneys 
are indicated. From time immemorial the alkalies and alkaline com- 
binations have been used with marked success in the management of all 
phases of the gouty diathesis. 

The treatment of acute gout necessitates, of course, different or more 
vigorous remedies than those required for the subacute or chronic forms 
with which the dental practitioner will be called upon to deal. 

Of the various alkalies, lithium compounds — the citrate and car- 
bonate — have been found well adapted to the milder phases of the 
disease. The writer has had much satisfaction in using, on the sugges- 
tion of Dr. E. C. Kirk, the tartarlithine lithium bitartrate, also alka- 
lithia prepared in the same form as the above-named compounds — com- 
pressed tablets containing five grains each ; one tablet three or four 
times daily will be found sufficient. Should the use of these lithia 
tablets not agree with the patient, the potassium carbonate in ten-grain 
doses, in some simple bitter — gentian or quassia water — three or four 



GOUTY PERICEMENTITIS. 531 

times daily, may be substituted. A valuable adjunct to the medicinal 
treatment is the free use of alkaline waters, which assist in the elimi- 
nation of waste products, though it is probable that the good effects 
attributed to these are largely due to the quantity of liquid consumed. 

The Saratoga, Vichy, alkaline waters of Wisconsin, the Marienbad, 
Carlsbad, Apollinaris, etc. have all been found efficacious. Should 
the patient be very dyspeptic, as is frequently the case, remedies 
directed to the digestive viscera are of course indicated. If anemia be 
a concomitant, iron and quinin will be necessary. A combination 
which has been found of great value in improving the quality of the 
blood is one of iron and a salt of potassium. Bland's pill, consisting 
of these two ingredients, is a desirable form for administration ; one 
three times a day will be sufficient. 

There is in addition one factor which may be regarded as therapeutic 
or at least prophylactic, and which is deserving of more than a passing 
notice, viz. the exercise of great care in the avoidance of injuries to the 
pericemental membrane, wherever there is a possibility of the presence 
of the unfortunate diathesis. 

However ingenious our interpretation of pathological conditions 
may be, and however plausible our deductions may appear, the ultimate 
test of their value will be the readiness with which they yield to and 
disappear under appropriate treatment. 

If pyorrhea alveolaris be a manifestation of the gouty diathesis, and 
the symptoms and pathological conditions which characterize it be ex- 
cited and maintained by the deposit and pressure of uric acid and its 
salts, it should be in general terms amenable to the therapeutic measures 
which have been efficacious in the treatment of all other forms of gout 
in other portions of the body. It must be borne in mind, however, that 
though a case be cured for a period of six months, or even a year, this 
does not preclude a relapse should the patient return to an improper 
diet or irregular mode of life. It is hardly necessary to say that this 
is true of all diathetic diseases. In individuals predisposed to uric acid 
accumulations, a new mode of life is to be instituted and followed with 
extreme care for a long period of time. 

The conclusions entertained may be represented in a condensed form 
in the following postulates : 

(1) Pyorrhea alveolaris of constitutional origin — which is its most 
destructive and unyielding form — primarily begins as a local inflam- 
matory disorder in tissues on the side of the root near the apical ex- 
tremity, and secondarily advances in the very large majority of cases 
toward the gingival borders. 

(2) The cause of this inflammation, or gingivitis and pericementitis, 
is the plasma exudation from the bloodvessels, freighted with salts 



532 PYORRHEA ALVEOLARIS. 

which in their deposition and crystallization upon the cementum of the 
root and infiltration of the more vascular tissues, exert the influence 
of foreign bodies and react as irritants. 

(3) The salts in question, as disclosed by chemical analysis, are cal- 
cium and sodium urates, free uric acid, and calcium phosphate. 

(4) The chemical nature of these salts indicates a condition of the 
blood in which there is an excess of uratic salts and uric acid due to 
either increased formation or imperfect elimination. 

(5) The excess of these salts, as is well known, is regarded by gen- 
eral pathologists as indicative of a faulty metabolism, and is the imme- 
diate cause of a series of local disturbances to which the term gouty has 
been applied, the nutritional disturbance giving rise to what is known 
as the " uric acid diathesis." 

(6) An attentive study and accurate observation of the various 
organs and tissues of patients suffering with pyorrhea alveolaris have 
disclosed the coexistence, in a very large proportion of them, of one or 
more local expressions of this constitutional diathesis. 

(7) Recognition of the fact that a constitutional malady presents 
itself, one phase of which only has claimed the attention of the dental 
practitioner, indicates that a treatment designed to be curative must 
have reference not only to the local expression, but especially to this 
important systemic condition as well. 

(8) Results from constitutional treatment in connection with the 
usual local applications in a number of well-authenticated cases of 
pyorrhea alveolaris have been so markedly satisfactory that the writer 
feels fully justified in his assumptions regarding the origin of the 
disease. 

While the foregoing pages embody views quite consistent with an 
extended experience, yet the writer fully appreciates the fact that many 
abnormal conditions closely allied in superficial characteristics to those 
above recognized and described may exist without any other local 
expressions indicating a uric acid dyscrasia. 

The association of the class of dental diseases included under the 
generic title of pyorrhea alveolaris with conditions of general mal- 
nutrition has been recognized by many writers during the past hun- 
dred years, but until within very recent times no systematic attempt 
had been made at their classification. Dr. M. L. Rhein, who has 
closely studied the relations existing between general disorders and the 
dental diseases, finding that many general diseases are accompanied by 
the symptom pyorrhea alveolaris, and that the dental disorder persists 
so long as the general disease is in activity, suggests that the diseases 
known under the latter title be divided into two classes — pyorrhea 
simplex and pyorrhea complex. : 



GOUTY PERICEMENTITIS. 533 

Under the head pyorrhea simplex are included all of those varie- 
ties and cases in which local therapeutic measures suffice to effect 
a cure. 1 

Pyorrhea complex covers those cases and varieties in which local 
therapeusis fails to subdue the dental disease, and which are associated 
with some perversion of general nutrition. This class is subdivided 
into four groups : (o) Those due to nutritional disorders such as gout, 
diabetes, chronic rheumatism, nephritis, scurvy, chlorosis, anemia, 
leukemia, pregnancy ; (6) Those occurring during attacks of acute infec- 
tive diseases, as typhoid fever, tuberculosis, malaria, acute rheumatism, 
pleurisy, pericarditis, syphilis ; (c) Those due to nervous disorders, 
cerebral diseases, spinal diseases, neurasthenia, hysteria ; (d) Con- 
ditions resulting from the action of toxic drugs — mercury, lead, 
iodids. 

Dr. Rhein believes from his studies that each member of the group 
of pyorrhea complex has a distinctive clinical expression, which might 
be utilized as diagnostic signs of the constitutional conditions. 

One who is familiar with oral abnormalities and able to differentiate 
them must be very liberal in the interpretation of causes in order to 
embrace the wide range of pathological conditions which, in some stages 
of development, present appearances that would or could very properly 
be termed pyorrhea alveolaris, yet whose very ready response to topical 
remedies would naturally suggest that they were not associated with a 
uric acid habit. While fully recognizing the fact that this uric acid 
dyscrasia can be associated with almost any disease which is a concomi- 
tant of malnutrition, we must remember and fully appreciate the fact 
that imperfect assimilation of food and faulty metabolism are often 
responsible for local abnormalities, and at the same time they may be 
factors in the establishment of a uric acid dyscrasia. 

In one's judgment of the soundness or unsoundness of theories or 
hypotheses, the fact must not be overlooked that affections of the kid- 
neys, the liver, the lungs, the heart, the mucous membrane, the stomach, 
etc. may exist without any other recognized expression, or we may have 
irritation of the pericemental membrane alone associated with any one 
of them, the disturbance of the normality of this tissue being severe or 
slight as the functional or organic abnormality of the organ is exalted 
or inconspicuous. 

While in the previous pages the treatment advocated had reference 
mainly to that form of pyorrhea the concomitant of the gouty diathesis, 
it must nevertheless be borne in mind that a similar condition of the 
pericemental membrane is at times associated with other perversions of 
the general nutrition, as pointed out by Dr. M. L. Rhein, and which 

1 Denial Cosmos, 1894, p. 780. 



534 PYORRHEA ALVEOLARIS. 

therefore must receive treatment especially adapted to the general con- 
stitutional state. 

Inasmuch as these constitutional conditions are complex in their 
manifestations and their medicinal and hygienic management almost 
exclusively in the hands of the physician, the duty of the dental prac- 
titioner is confined largely to the question of diagnosis ; the local treat- 
ment, however, must be varied in accordance with the peculiarities of 
the local pathological condition. 



CHAPTER XX. 

DISCOLORED TEETH AXD THEIR TREATMENT. 

By Edward C. Kirk, D. D. S. 



Discoloration of a tooth is consequent upon death of its pulp. 
While death of the pulp does not always or necessarily involve dis- 
coloration of the tooth structures, yet when the condition does exist the 
general cause is as stated. Reference is here made to a progressive 
interstitial staining of the entire dentin structure, and is exclusive 
of certain metallic stains, and also localized stains resulting from the 
imbibition of pigmentary matters which occasionally are observed where 
small areas of dentin have become denuded of enamel covering, or 
where the latter has been so imperfectly formed as to afford an in- 
sufficient barrier to the ingress of pigmentary matters from the food 
or oral secretions. 

Three classes of conditions are presented for consideration and treat- 
ment : First, cases where discoloration has resulted from death of the 
pulp due to causes other than its exposure ; second, discoloration from 
pulp death consequent upon exposure ; and third, special discolorations 
due to adventitious causes superadded to the conditions affecting the 
cases included in the foregoing second division. 

Any of the numerous traumatic causes which bring about death of 
the pulp, e. g. blows, sudden contact with hard substances, biting 
threads, violent thermal shocks, the injudicious application of continuous 
force in regulating, or the application of arsenous oxid to the dentin 
(see p. 425), where no exposure or only minute exposure of the pulp 
exists, may produce hyperemia and congestion of the pulp, or strangu- 
lation of its circulatory system, the formation of emboli, thrombus, 
hemorrhagic infarct, etc., leading to a breaking down of the corpus- 
cular elements of the blood, the escape of hemoglobin from the stroma 
of the red corpuscles, its solution in the blood plasma, and resulting 
infiltration of the tubular structure of the dentin by the hemoglobin 
solution, giving the tooth a distinctly pinkish hue when examined by 
direct or transillumination. 

Teeth so affected rapidly change in color through various gradations 
in tint from the original pinkish hue, which becomes yellow ; this, grow- 
ing darker, passes into brown, and after the lapse of considerable time 
the tooth may become a permanent slaty gray or black. 

535 



536 DISCOLORED TEETH AND THEIR TREATMENT 

The violence of the pulpitis preceding the death and disintegration 
of the pulp, in a considerable degree determines the rapidity of the 
process of subsequent tooth discoloration. Where congestion of the 
pulp has been relatively slight and the necrotic process has proceeded 
slowly, the sudden infiltration of the dentin with hemoglobin does not 
occur, consequently the initial change in color following complete death 
of the pulp may be so slight as to escape detection except upon most 
searching examination with special means of illumination, and even 
then may be manifested only by a slight diminution in the normal 
translucency of the tooth as compared with adjoining teeth. Such teeth, 
however, if permitted to remain untreated, eventually grow darker, 
and while they may not acquire a degree of discoloration equal to those 
which have suffered sudden and violent death of the pulp, still they 
become so unsightly as to demand treatment for the restoration of 
their normal color. 

The Rationale of the Process of Discoloration. — In teeth dis- 
colored as a consequence of the death of the pulp without its exposure — 
viz. those of the first class — it is evident that the sources of pigmenta- 
tion are internal to the tooth and are to be sought for solely in the 
products of decomposition of the elements of the pulp tissue and of its 
vascular supply. 

The proteid elements of the pulp tissue are complex combinations 
of carbon, oxygen, hydrogen, nitrogen, sulfur, and phosphorus, which 
in their gradual breaking down by the process of putrefactive decom- 
position are split up finally into carbon dioxid, water, ammonia, and 
hydrogen sulfid, with possibly the formation of traces of phosphatic 
salts. The group of substances entering into the composition of the 
histological elements of pulp tissue contains no constituents which in 
the progressive changes resulting from putrefactive decomposition 
should form compounds likely to cause permanent discoloration of 
the tooth structures. 

When, however, the vascular supply is considered as a factor, the 
explanation of the cause of discoloration in the cases in question 
becomes reasonably clear. The red blood corpuscles contain as their 
characteristic component hemoglobin or oxyhemoglobin according as the 
blood is venous or arterial, and this substance is its essential coloring 
ingredient. When undergoing gradual decomposition, hemoglobin 
passes through a variety of alterations in its chemical constitution, 
accompanied by a corresponding series of color changes. 

A familiar illustration of these color changes is furnished by the 
cycle of color alterations witnessed in a bruise. Immediately following 
an injury to the flesh, of the character alluded to, an extravasation of 
blood in the bruised territory occurs, causing undue reddening of the 



RATIONALE OF THE PROCESS OF DISCOLORATION. 537 

skin ; this is soon followed by an increasing darkening of the tissue, 
until there results what is popularly termed a " black-and-blue spot." 
Further decomposition of the coloring matter of the extra vasated blood 
induces a variety of color changes ranging through the scale of yellows 
and browns, until the pigmentary matter is finally removed by absorp- 
tion through the capillary bloodvessel system of the part. 

In passing through its cycle of color changes, hemoglobin undergoes 
several alterations in composition during which a number of definite 
compounds are formed, each having marked chromogenic features. Of 
these decomposition products, methemoglobin (brownish red), hemin 
(bluish black), hematin (dark brown or bluish black), and hematoidin 
(orange), are the most important and best known. While the gradual 
decomposition of the coloring matter of the blood here noted may and 
doubtless does account for certain phases of tooth discoloration, other 
factors which exert a profoundly modifying influence upon the process 
are yet to be considered. 

The putrefactive decomposition of the proteid elements of the pulp 
results, as before stated, in the production of hydrogen sulfid in con- 
siderable quantity. The albumins contain from 0.8 to 2.2 per cent, of 
sulfur (Hammarsten) which in the splitting up of the compound during 
putrefaction yields a large amount of hydrogen sulfid. In pulp decom- 
position this hydrogen sulfid is generated in contact with the hemoglobin 
and necessarily exerts a marked modifying action upon the decomposi- 
tion process of that substance. Miller says, " If a current of sulfuretted 
hydrogen is conducted through fresh blood or a solution of oxyhemo- 
globin in the presence of air or oxygen, sulfomethemoglobin is formed, 
which is greenish red in concentrated solutions and green in dilute solu- 
tions. If we lay a freshly extracted tooth in a mixture of meat and 
saliva so that a part of the enamel surface remains free, and moisten 
the surface with blood, it will take on a dirty-green color if kept at 
blood temperature in an absolutely moist condition for from twenty-four 
to forty-eight hours. It is quite possible that the dirty-green deposits 
which form in putrid conditions of the mouth, in stomatitis mercurialis, 
scorbutica, gangrenosa, etc., or even in inflammatory conditions of less 
importance, as well as in cases of absolute neglect of the care of the 
mouth, may owe their green color to the presence of sulfomethemo- 
globin." 

As in pulp decomposition hydrogen sulfid is being formed in the 
presence of hemoglobin, this fact warrants the belief that a combina- 
tion takes place resulting in the formation of this same compound, 
which Miller regards as productive of certain stains upon the external 
surface of the teeth. 

The slaty gray or bluish pigmentation always noticeable upon the 



538 DISCOLORED TEETH AND THEIR TREATMENT. 

visceral walls and frequently beneath the skin of animal bodies under- 
going putrefactive degeneration is a familiar example of the action of 
hydrogen sulfid upon decomposing hemoglobin in hemorrhagic extrava- 
sations, and is a process and form of pigmentation exactly analogous to 
that which is here described as taking place in the dentinal structure 
from putrefactive decomposition of the pulp. " When red corpuscles 
are just beginning to disintegrate, the coloring matter formed is hemo- 
globin ; but the yellow and brown granular masses found in cells and 
lying free in tissues are, as a rule, derivatives of hemoglobin, not hemo- 
globin itself. These derivatives are divided into two groups according 
as they contain iron or not, the former being called hemosiderin, the 
latter hematoidin." l " When acted upon by ammonium sulfid (a deriv- 
ative of putrefactive decomposition of albumin) hemosiderin becomes 
black, iron sulfid being formed." 2 Grohe 3 believes that as a result of 
putrefaction iron is liberated from its compound with hemoglobin, so 
that when thus freed it readily combines with the hydrogen sulfid. 

Iron is the most important element to be considered in the list of 
factors causing the discoloration of this group of cases. It is the iron 
constituent of the red corpuscles which is the essential chromogenic 
factor from first to last in their cycle of color changes. 

The process of putrefactive decomposition consists of a series of 
chemical changes wrought out through the agency of micro-organisms, 
involving the breaking down by successive stages of highly complex 
organic compounds and their resolution into compounds of much sim- 
pler constitution. It is not known to what extent this splitting up of 
the components of the pulp and its vascular elements is ultimately car- 
ried in the series of changes resulting in the permanent discoloration 
of the tooth. From what is known of the ultimate composition of the 
compounds involved it may, however, be safely inferred that, reduced 
to its lowest terms, the result would be the formation of iron sulfid, the 
elements of which, with the exception of some unimportant alkaline and 
earthy salts, are the only ones entering into the original compounds 
which are fixed and therefore capable of forming a stable residuum in the 
tubular structure of the dentin. While iron sulfid as such cannot be 
held wholly accountable for the final bluish-black color of a tooth which, 
has reached the stage of permanent discoloration, the pigmentation is 
almost certainly due either to it or to some allied compound in which 
iron and sulfur, with some organic constituents, largely enter, and which 
by a further slight decomposition would yield true iron sulfid. 

The significance and importance of a recognition of the possible 
presence of the iron compound as a factor in tooth discoloration is 
further brought out in the study of bleaching methods (pp. 542 and 558). 

1 Ziegler, General Pathology, 1895. 2 Ibid. 3 Virchow's Archiv., Bd. xx. 



DISCOLORATION FOLLOWING DEATH OF THE PULP. 539 

Discoloration of Teeth following Death of the Pulp consequent 
upon its Exposure. — When death and decomposition of the pulp is 
consequent upon exposure of that organ, through caries or otherwise, to 
the irritative influences of infective agents present in the oral secretions 
and food, or to thermal shock, etc., the putrefactive process involving 
the pulp tissues is modified in character and rapidity to a degree which 
may affect the character of the resulting discoloration. Thus the yel- 
lowish or brownish discoloration so often seen in teeth whose pulps 
have been devitalized through systemic or traumatic causes, and which 
in many cases appears to be more or less permanent in character, is 
rarely observed in those teeth whose pulps have been devitalized through 
exposure by caries. 

In these latter cases the progress of the putrefactive process is com- 
paratively rapid, the conditions being more favorable so that the color- 
ing matter of the blood is sooner reduced to its lowest terms in the scale 
of decomposition products, i. e. to the slaty blue or black pigmentation 
before noted. In addition to the increased rapidity of putrefactive de- 
composition incident to cases of discoloration following pulp exposure, 
another and important modifying factor in the process of discoloration 
is the ingress afforded to the oral fluids, food materials, and other ad- 
ventitious substances which find their way into the mouth and ulti- 
mately, through the open cavity of the tooth, to its pulp canal and 
thence to the tubular structure of the dentin. These extraneous sub- 
stances, in the course of time, may infiltrate the tooth structure, and 
while no especially noticeable or characteristic effect may be observed 
so far as color is concerned, yet they frequently exert an influence upon 
the coloration of the tooth which so alters its character as to render 
successful bleaching treatment extremely difficult and a resort to special 
methods or a variety of methods necessary. 

The introduction of fatty or oily substances or of astringent and 
coagulant matters, for example, may act upon the coloring matter in 
such a way as to permanently " set " it in the same manner that mor- 
dants form insoluble compounds or lakes with the dye-stuffs used in 
the dyeing of textile fabrics. 

Another and important class of substances which frequently are the 
cause of staining of the tooth structure are metallic salts which are used 
in dental therapeutic treatment or are accidentally formed during the 
application of corrosive medicaments to the teeth, through the action of 
such remedies upon fillings in situ or upon the instruments by which 
the applications are made. For example, the use of iodin or sulfuric 
acid in connection with steel instruments and the subsequent use of 
medicaments containing tannin as an ingredient. 

The treatment of these conditions w T ill be separately considered. 



540 DISCOLORED TEETH AND THEIR TREATMENT. 

Tooth-Bleaching. — Use of Ohlorin. 

Nature of the Problem Involved in Tooth-Bleaching'.— The 
bleaching process is dependent upon a chemical reaction between a com- 
pound having color and some substance capable of so affecting its com- 
position that the color is discharged, or, in other words, of so affecting 
the integrity of the color molecule as to destroy its identity, which 
results in a loss of its distinguishing characteristic, viz. its color. 

The substances concerned in discoloration of tooth structure, as has 
been previously shown, are derived from the pulp and its vascular 
elements and the organic contents of the tubular structure of the dentin, 
through the gradual putrefactive processes which become operative 
subsequent to the death of the pulp. These pigmentary products of 
pulp decomposition we know to be organic in character; and further, 
that they exhibit the property of color by virtue of definite conditions 
of molecular composition- — that is to say, a certain arrangement of a 
definite kind and number of atoms has resulted in the formation of a 
molecule having its individual group of chemical and physical prop- 
erties, among which latter is a characteristic color. 

Whatever brings about an alteration in the composition of the mole- 
cule at once destroys the identity of the matter so treated. Hence if 
we can act upon the coloring matter which gives rise to the staining of 
a tooth by means of an agent capable of effecting an alteration in the 
atomic arrangement or composition of the color molecule, we may expect 
to remove or discharge its color feature. 

Two general classes of substances have been successfully used as 
bleaching agents : First, those which act by virtue of their power to 
evolve oxygen in the active or nascent condition, and known as oxidiz- 
ing agents ; second, those which act in an opposite manner by virtue 
of their strong affinity for oxygen and which are called reducing agents. 
The oxidizing bleachers destroy the identity of the color molecule by 
seizing upon its hydrogen element to form water. The reducing agents 
act by removing the oxygen atom from the color molecule to form by- 
products depending upon the character of the reducing agent used. 

Chlorin and its associates iodin and bromin act as indirect oxidizing 
bleachers ; the dioxid of hydrogen and of sodium are direct oxidizers. 
Potassium permanganate may also be classed with this group, though its 
successful use as a bleaching agent depends upon a subsequent treat- 
ment of the substance to be bleached with some solvent capable of re- 
moving the manganese dioxid formed as a by-product of the action of 
the permanganate. It has somewhat extensive and satisfactory use as 
an agent for bleaching sponges, and has been used for bleaching teeth, 
but is of greatly inferior value to other agents for the latter use. 



TOOTH-BLEACHING— USE OF CHLORIN. 541 

The only agent belonging to the group of reducing bleachers which 
has thus far been found available for bleaching teeth is sulfurous oxid, 
either in the gaseous condition or in aqueous solution. 

Chlorin as a Bleacher. — The general use of chlorin as a bleaching 
agent in the arts no doubt suggested its use in the treatment of tooth 
discoloration. Its introduction as a tooth-bleaching agent, as well as the 
assembling of the general principles of tooth bleaching into a co-ordi- 
nate system, are due to Dr. James Truman, whose method depends upon 
the liberation of chlorin from calcium hypochlorite, commonly called 
bleaching powder or " chlorinated lime," in the pulp chamber and cav- 
ity of decay in the tooth. Chlorin is liberated from the bleaching pow- 
der by the action of dilute acetic acid ; this taking place in contact with 
the discolored structure, it is rapidly bleached as a result of the action 
of the chlorin upon the coloring matter contained in the dentinal tubules. 
Numerous modifications of this original method of bleaching tooth struc- 
ture have been suggested, but, as the ultimate result in each is accom- 
plished through the activity of chlorin, a rational understanding of the 
mode of action of chlorin in this relation is of importance as an aid 
to the intelligent use of those methods for tooth-bleaching which are 
dependent upon or owe their efficacy to that agent. 

Chlorin is an elementary gaseous body, greenish in color, soluble in 
water, having a disagreeable odor, intensely irritating to the air-passages 
when inhaled, and poisonous when breathed in sufficient quantity. It 
has a strong affinity for all metallic bodies, entering into direct combi- 
nation with a number of them, under favorable circumstances, with 
great energy — forming, as a rule, compounds that are soluble in water. 

One of its distinguishing features and one which is directly concerned 
in its use as a bleaching agent is its strong affinity for hydrogen. So 
strong is this affinity, that when a molecule of chlorin is brought into 
contact with a molecule of water under favorable conditions, the hydro- 
gen of the water molecule is seized upon by the chlorin to form chlor- 
hydric acid and the oxygen is set free in the nascent state, a condition 
under which its oxidizing powers are exhibited in their greatest intensity. 
This powerful affinity of chlorin for hydrogen enables it to decompose 
many other hydrogen-containing molecules in a similar manner, form- 
ing chlorhydric acid and destroying the identity of the matter acted 
upon. 

It has been shown that all organic compounds which are the products 
of the vital processes of the animal body contain hydrogen as an im- 
portant constituent. This applies also to the decomposition products 
whose presence in the tubular structure of the dentin is the cause of 
tooth discoloration. 

These organic stains exhibit the property of color by virtue of 



542 DISCOLORED TEETH AND THEIR TREATMENT. 

certain definite conditions of molecular composition ; hence, if chlorin 
is caused to act upon the coloring matter which causes the staining of 
a tooth, by seizing upon and combining with the hydrogen of the 
organic pigment, the identity of the compound as such is destroyed, 
and its characteristic feature, that of color, is lost. 

The principle here outlined is involved in what is termed the direct 
action of chlorin in bleaching. There is, however, another method by 
which chlorin is believed to act as a bleacher in which its function is 
indirect. In some cases it has been observed that chlorin fails to act 
except in the presence of moisture, and the rationale of this is that the 
bleaching under such conditions is effected by nascent oxygen liberated 
from the water molecule when the chlorin combines with its hydrogen 
to form chlorhydric acid ; thus : Cl 2 + H 2 = 2HC1 + O. That such 
is the nature of the process in many cases is a reasonable deduction 
from the behavior of chlorin under analogous conditions where it acts 
indirectly as an oxidizing agent. 

Whatever may be the exact nature of its ultimate action, it is to be 
borne in mind that its bleaching effect is due solely to the alteration 
which it makes in the composition of the color molecule, and that it 
has no solvent power whatever on the organic matter upon which it 
acts. It changes its characteristics, but does not remove it by solution. 
It should be also noted in this connection that the chlorin compounds 
of most of the metallic elements, especially when in dilute solution, are 
almost colorless as compared with many of the other metallic com- 
pounds — the oxids and sulfids for example. Hence it is that where 
stains owe their color to the presence of certain organic compounds 
with some of the metals, or even where the coloration is due to decom- 
position products of hemoglobin, the color may readily be discharged 
by chlorin, but if the iron chlorid thus produced remains in the tooth 
structure it is gradually decomposed and new combinations of it are 
liable to occur, which results in a return of the discoloration. 

All tooth-bleaching methods should aim not only to discharge the 
color by suitable chemical means, but should go farther than this and, 
as far as it may be possible to do so, remove all organic debris from the 
tubules, for as long as any remains the tendency to a return of the dis- 
coloration is always a possible and indeed probable menace to the com- 
plete and permanent success of the operation. 

Where the tubular contents cannot be successfully removed, the 
tendency to a return of discoloration may be combated by hermetically 
sealing the tubular orifices with an impermeable resinous varnish or 
permanently coagulating them. This feature is described more fully in 
relation to the details of the bleaching procedure. 

Teeth Suitable for the Bleaching" Operation. — In deciding upon 



TOOTH-BLEACHING— USE OF CHLORIX. 543 

the advisability of attempting the bleaching operation in any given case, 
the general conditions which determine the judgment of the operator 
with respect to all dental operations should govern his course. 

As all therapeutic and restorative measures in dentistry are a series 
of compromises with disease conditions or their sequelae, it is the duty 
of the operator under all circumstances to capitulate upon the basis of 
greatest advantage to the patient. Therefore if discoloration of a tooth is 
practically the only factor in the problem presented by a given case, 
the effort should be made to restore the organ to its normal condition 
of color. The same rule should be applied to all cases of discolored 
teeth in which structural loss by caries or fracture has not been so great 
as to preclude a satisfactory restoration by proper filling or replace- 
ment of the 'lost structure by a porcelain inlay. The cases in which it 
is not advisable to attempt a bleaching operation are only those in which 
loss of structure is so extensive as to require a crowning operation. 

In the judgment of many operators it is considered useless to at- 
tempt the bleaching of any teeth excepting the incisors, because of the 
difficulty and length of time frequently required for the successful 
bleaching of canines, bicuspids, and molars, owing to the thickness of 
their walls and the consequent depth of structure requiring treatment. 
It is also held to be useless to attempt the bleaching of teeth which 
have been discolored by metallic stains throughout their structure. 
The fallacy of such a view is self-evident when it is considered that if 
any portion of the dentinal structure of a discolored tooth is amenable 
to the bleaching treatment, its complete restoration is simply a question of 
continuance or repetition of the operation until the desired end is attained. 

With regard to discoloration by metallic stains, while teeth so af- 
fected present problems of great complexity, and require not only 
special study but the application of special methods of treatment based 
upon proper recognition of the chemical relationships involved between 
the nature of the stain and that of the agent used for its removal, the 
attempt should be made in justice to the patient, even though ultimate 
failure result, in order that the necessity for destruction of the natural 
crown for the purpose of its replacement by an artificial substitute may, 
if possible, be postponed for as long a period as may be attainable. 

Preparation of the Tooth for the Operation of Bleaching". — Cer- 
tain general details are necessary to be observed in the preparation of 
teeth for the bleaching operation, whatever may be the method of treat- 
ment employed. 

Appropriate treatment for the removal of all septic matter from the 
pulp chamber and canal, and for the relief of any existing condition of 
irritation of the pericemental membrane and tissues of the apical region, 
should have been carried out and the tooth brought to the condition in 



544 DISCOLORED TEETH AND THEIR TREATMENT 

which permanent closure of the apical foramen of the root may be safely 
performed. 

The rubber dam should be adjusted with especial care and only 
include the tooth to be bleached. If two adjoining teeth are to be 
bleached they may both be isolated by the dam, but in no case should 
one or more adjacent normal teeth be included with the tooth to be 
bleached. While the inclusion of teeth adjacent to the one which is the 
subject of any ordinary dental operation is in nearly all cases desirable, 
there are good reasons why such a plan should not be pursued in the 
bleaching procedure. The chemicals used for the purpose may possibly 
have some disintegrating or solvent action upon the enamel structure, 
and such action, should it occur, should be confined strictly to the tooth 
undergoing treatment and held within the limits of safety by close 
observation and appropriate treatment, which conditions cannot be as 
thoroughly controlled and the process as satisfactorily managed when 
several teeth are included within the territory of operation. 

Furthermore, as nearly all of the bleaching agents used or those 
which are employed as adjuvants in the process have a more or less 
irritative or escharotic effect upon the soft tissues of the mouth, extra 
precautions must be taken, in adjusting the dam, against leakage at its 
attachment to the cervix of the tooth. As the chances of leakage are 
greatly multiplied when several holes are punched in the dam for ad- 
justment to as many teeth, it is for this reason also that no other than 
the tooth to be treated should have the dam adjusted to it. 

Supposing the tooth to be an upper incisor, the dam should be 
slipped over it and the margin of rubber encircling the cervix should 
be gently carried under the free margin of the gum either by means of a 
small flat burnisher of suitable angle and curvature, or by means of a 
waxed floss-silk thread. One or two turns of a ligature should then be 
thrown around the cervix below the dam to hold it securely in place. 
The dam may be fixed with greater security, especially as against any 
accidental traction made upon it during the operation, by fastening it 
with a ligature made as follows and thrown around its cervix : 

A piece of waxed ligature silk about eighteen inches in length has 
a large knot tied at about its middle portion by making six or eight 
turns of the thread loosely around the end of the index finger of the 
left hand. Upon withdrawing the finger a series of loops are had 
through which one of the free ends of the thread is now passed, as 
in making the first half of a flat knot, as illustrated in Fig. 480. 
By drawing upon the free ends of the thread until all of the loops 
are closed upon themselves, a hard knot of more or less spheroidal 
shape is formed about midway between the ends of the ligature. The 
ligature so prepared is placed around the tooth in such a manner that 



TOOTH-BLEACHING— USE OF CHLOBIN. 545 

the knot as described shall be located upon and at the middle portion 
of the palatal cervical margin. A half knot is then made by tying the 
ligature in front so that it shall rest directly opposite the palatal knot, 
viz. at the middle portion of the labial cervical margin. The ligature 
is drawn into fairly close contact with the tooth, and, with both ends 
held firmly in the left hand and drawn somewhat tense, the portion 
encircling the tooth is firmly but gently forced up against the rubber 

Fig. 480. 




dam and gingival margin, the ligature at the same time being drawn 
tightly until the anatomical constriction of the tooth at its cervix will 
serve to hold it from slipping downward, especially upon the palatal 
aspect of the tooth. 

When the ligature is found to be securely placed as described, the 
knot upon the labial aspect is completed and further enlarged in bulk 
by re-tying the thread four or five times. The free ends of the ligature 
should then be cut off close to the knot. As an additional safeguard 
against leakage of irritating bleaching agents through the cervical 
attachment of the dam, and out upon the soft tissues, it is well after 
making the tooth perfectly dry to paint the ligature and a narrow band 
of its adjacent territory with chloro-percha, which will effectually prevent 
any accident from leakage. 

The placing of a large knot upon the palatal aspect at the cervical 
margin has another decided advantage in that it not only holds the dam 
more securely against slipping downward, but holds it away from the 
palatal surface, which is ordinarily the point of entrance to the pulp 
chamber and canals in these cases. The point of canal entrance may, 
however, be through an approximal cavity, if such an one affords 
sufficient access. 

The canal filling in all cases of bleaching without exception should 
be gutta-percha. No other material used for canal filling possesses the 
generally desirable qualities needed for that purpose in this class of 
cases. The extent of the canal filling should include one-third, or at 
least not over one-half, of the distance from the apex. A considerable 
portion of the canal beyond the level of the gingival margin is thus 
left unfilled in order that the coronal end of the root may be bleached 
as well as the tooth crown. This is especially necessary where more 
or less recession of the gum from its normal attachment has occurred, 

35 



546 DISCOLORED TEETH AND THEIR TREATMENT. 

leaving the cervical cementum exposed to the action of the oral fluids, 
food, etc., which have a tendency to cause discoloration of the exposed 
root tissue. 

The root being filled as directed, all fillings wherever existent in the 
tooth should be removed. This is a preliminary procedure which 
should not be omitted in any case, but where any bleaching method is 
used which involves the employment of chlorin as the active agent it 
becomes imperatively necessary for reasons which are explained in con- 
nection with the description of the chlorin methods (page 547). Aside 
from other considerations, the removal of all fillings preparatory to the 
bleaching operation has a decided value in facilitating the process by ex- 
posing an increased area of the dentinal structure and thereby permit- 
ting the action of the bleaching agent over a larger territory of ingress. 

When all fillings or softened tooth structure have been removed, as 
well as all septic and extraneous matter of whatever character, by 
mechanical process, the tooth should be washed thoroughly with dilute 
ammonia water, or better with a hot solution of borax in distilled water 
in the proportion of $j to fgj. The object of this treatment is to re- 
move by saponification and solution all fatty matters which may obstruct 
the ingress of the bleaching agent into the dentinal structure. 

In nearly all cases where discoloration has occurred from a decom- 
posed pulp and where the canals and pulp chamber have been left 
untreated, there will be observed, on opening into such a pulp 
chamber for the first time, a dark layer of oily or greasy material 
lining its walls. The thorough removal of this dark layer should 
be effected prior to any attempt at bleaching, as it appears to prevent 
the ingress of the bleaching agent into the dentinal structure. The 
most satisfactory method for removing the dark greasy layer is by the 
use of suitable instruments — either properly shaped spoon or hoe ex- 
cavators or round burs in the engine. The thorough removal of this 
layer necessitates free access to the pulp chamber, which should be 
as a general rule obtained by means of an ample opening upon the 
lingual aspect of the tooth in the case of incisors, and through the 
morsal surface in bicuspids, etc. 

Having by mechanical means and through the agency of borax or 
ammonia and hot distilled water effected a thorough cleansing of the 
interior portion of the tooth, it should next be dried to the extent of 
having all superfluous moisture removed, and it will then be in condi- 
tion for the application of whatever method of bleaching may be chosen 
for the particular case in hand. 

Dr. James Truman's Method. — This, as before stated, was the first 
method successfully employed for bleaching teeth. It consists in liberat- 
ing chlorin from ordinary chlorinated lime by means of a weak acid 



TOOTH-BLEACHING— USE OF CHLOBIN. 547 

in the pulp chamber of the tooth. Any acid will effect the liberation of 
chlorin from the bleaching powder, but acetic, tartaric, or oxalic are 
generally used. Care must be observed in selecting a good quality of 
bleaching powder, as that substance rapidly undergoes decomposition 
spontaneously, especially in a moist atmosphere. Good chlorinated lime 
is a dry powder having a strong odor of chlorin. If it is moist or pasty 
and has but a feeble odor it should be rejected as worthless. Brands 
of bleaching powder dispensed in metallic packages should not be used, 
as they are invariably contaminated with metallic chlorids due to the 
slow action of the contents upon the containing package. This is par- 
ticularly the case where sheet-iron boxes are used. The return of dis- 
coloration in many cases after bleaching by the Truman method is 
undoubtedly due to the use of bleaching powder so contaminated. 
The powder dispensed in glass bottles or in paraffined paper cartons 
is more reliable. 

Its application to the tooth may be effected in several ways : 
(a) By packing the dry powder in the pulp chamber and then moist- 
ening the latter with the acid ; 

(6) By mixing the powder with sufficient distilled water to make a 
coherent mass which is more easily manipulated, then packing it in the 
pulp chamber and applying the acid ; 

(c) By first moistening the interior of the tooth with the acid, next 
dipping the instrument into the powder and then into the acid, each 
time carrying the mixed materials into the tooth until the desired 
change of color is produced. 

Probably the most satisfactory method is to pack the dry powder 
into the tooth and apply the acid to it, after which immediately seal the 
cavity with a single pellet of gutta-percha. By using a 50 per cent, 
solution of acetic acid the evolution of chlorin will take place with a 
satisfactory degree of uniformity, and not so rapidly as to interfere with: 
its penetration throughout the discolored tubular structure of the dentin.. 
The bleaching mass may be sealed in place by means of oxyphosphate 
of zinc if desired, but it is usually unnecessary to use anything other 
than gutta-percha or one of the soft temporary stopping materials for 
this purpose. 

The case may be dismissed for one or two days and the treatment as 
outlined repeated at similar intervals until the tooth is restored to 
normal color. 

The instruments used in connection with this process should be of 
vulcanite, bone, ivory or wood. Upon no consideration should steel,, 
gold, or platinum instruments be used, as chlorin acts directly upon 
each of these metals, forming soluble chlorids which if carried into the 
tooth structure will give rise to a permanent staining of most intract- 



548 DISCOLORED TEETH AND THEIR TREATMENT. 

able character. The only metals which may be safely used in connec- 
tion with any chlorin process of bleaching are zinc and aluminum, 
the chlorids of which are colorless. Aluminum instruments for the 
purpose may be quickly improvised out of wire or heavy plate. Gold 
instruments have been recommended, but they are open to the very 
grave objection of forming a chlorid by direct combination with chlorin, 
which salt is one of the most important staining media known to the 
histologist ; as a matter of fact the writer has seen several cases 
where a permanent purple staining of the tooth has resulted from 
neglect to remove gold fillings before applying the chlorin method of 
bleaching, and there is certainly no reason why the same result should 
not follow the using of gold instruments in the same connection. 

When the tooth has been restored to its proper color it should be 
thoroughly washed with very hot distilled water, dried out with bibu- 
lous paper and thoroughly desiccated with a current of dry hot air, 
after which the canals, pulp chamber, and cavities should be filled with 
oxy chlorid of zinc. 

The final filling of the cavities of entrance and of decay should be 
postponed until by a lapse of considerable time the permanence of the 
operation has been established. This probationary period may with 
advantage be prolonged to four or six months. 

^The final washing of the tooth with hot distilled water previous to 
the insertion of the oxychlorid of zinc filling is a feature of the opera- 
tion which requires special care and attention. As left after the appli- 
cation of the bleaching agent, the pulp chamber and canals and denti- 
nal structure are filled with free chlorin in solution, calcium acetate, or 
other salt of calcium depending upon the nature of the acid used in 
the process, and some undecomposed bleaching powder. These sub- 
stances should be thoroughly removed by the hot-water douche. At 
least a pint of water should be strongly injected into the interior of the 
tooth by means of a large bulb syringe, before the dam is removed. A 
towel held in close proximity to the tooth will catch the water as it re- 
turns from the tooth and protect the clothing of the patient. Distilled 
water should in all cases be used for this irrigating douche, as river 
water and many other specimens of water from natural sources contain 
iron in solution, which could readily become a contaminating factor 
leading to subsequent return of discoloration. 

Oxychlorid of zinc is selected as the permanent filling for the pulp 
chamber for the reason that it is necessary to so act upon the bleached 
organic residuum in the tubular structure as to prevent any alteration 
of its character which may result in the production of a subsequent 
coloration. Zinc chlorid possesses the property of converting many 
organic substances into unalterable compounds by its coagulant action, 



TOOTH-BLEACHING— USE OF CHLORTN. 549 

thus tanning or mummifying animal tissue and preserving it indefi- 
nitely. A mass of oxychlorid of zinc, before it sets, i. e. before chemical 
combination takes place between the oxicl-of-zinc powder and the zinc 
chlorid liquid, is functionally free zinc chlorid — and as a matter of fact 
the properties of zinc chlorid are manifested by such a mass for a con- 
siderable period of time after the mass has apparently set. When 
introduced into the pulp chamber and canal, its action upon the organic 
debris in the tubuli is as stated, and the material, if the operation has 
been successfully performed, is effectually prevented from further alter- 
ation, upon which condition the permanence of the operation depends. 

Another method for preventing subsequent alteration of the bleached 
organic debris in the tubular structure is to thoroughly desiccate the 
tooth by means of the hot-air blast and saturate the dentin with some 
insoluble resinous varnish, such as copal ether varnish, or what is still 
better the solution of trinitrocellulose in methyl alcohol, known in com- 
merce as " kristaline " or at the dental depots as " cavitine." The 
pulp chamber and canals may then be filled with any suitable filling. 

As between the oxychlorid of zinc filling and the varnish lining the 
choice in general should be of the former. The varnish lining is adapt- 
able more especially to cases of long standing where complete liquefac- 
tion of the tubular contents has left them practically empty, and where 
as a consequence there is nothing upon which zinc chlorid can exert its 
coagulating effect. 

Other Chlorin Methods. — The solution of chlorinated soda known 
as Labarraque's solution, or Liquor soda? chloratse U. S. P., may be 
applied to the previously desiccated tooth structure until the dentin 
is saturated with the solution, after which an application of a dilute 
acid is made which liberates chlorin. The chemical principles in- 
volved are exactly analogous to those upon which the method with 
bleaching powder depends, the only difference being that the source 
of the active agent, chlorin, is in one case its calcium compound, which 
is a dry powder, and in the second case the analogous soluble sodium 
compound of chlorin is the material from which the active agent is 
evolved. 

The precautions necessary to be observed are exactly the same as 
those required in Truman's method already described. The results 
obtained by this process are not as thorough or as satisfactory as by the 
Truman method. 

Chlorin per se has been used for tooth-bleaching, and was the basis 
of a method devised by Dr. E. P. Wright of Richmond, Ya. 

"Wright's method involved the use of a complicated apparatus by 
which a glass vessel of about a half-liter capacity, and filled with chlorin 
previously prepared in the laboratory, was connected by means of a 



550 DISCOLORED TEETH AND THEIR TREATMENT. 

doubly perforated rubber stopper and two pieces of rubber tubing with 
a glass adapter, around the open end of which was tied the rubber dam 
encircling the tooth to be operated upon. About midway of the length 
of one of the rubber tubes connecting the chlorin reservoir with the 
rubber dam was interposed an ordinary syringe bulb, so arranged with 
hard-rubber valves that by repeatedly compressing and relaxing it the 
chlorin would be drawn from the reservoir and injected through a glass 
delivery jet into the pulp chamber. Return of the gas to the reservoir 
was provided for by the second piece of rubber tubing first alluded to. 
In this way a continuous jet of chlorin was thrown into and about the 
tooth, which , by means of the rubber dam, was placed in a close cham- 
ber forming a part of the apparatus ; none of the gas could escape into 
the surrounding atmosphere. The complexity of the apparatus was 
a formidable obstacle to the general use of the method and it was 
abandoned, though the results were in many cases very satisfactory. 

The Dioxid Bleaching Methods. 

Bleaching by Means of the Dioxid of Hydrogen and the Dioxid 
of Sodium. — The commercial introduction of solutions of hydrogen 
dioxid marked a new era in the operation of bleaching discolored teeth. 
The bleaching property of hydrogen dioxid had been known to chemists 
for many years, but the application of this property to tooth-bleaching 
dates from the medicinal use of hydrogen dioxid solutions for the treat- 
ment of purulent conditions of the pulp canal and about the roots of 
teeth. When applied in the canals of discolored and infected teeth it 
was observed that a noticeable bleaching of the discolored structure 
resulted. The hint thus given was further studied until it was found 
that under proper conditions the whole structure of a discolored tooth 
might be successfully restored to normal color. 

The earlier preparations were found to be lacking in strength ; 
aqueous solutions containing more than 3 or 4 per cent, of absolute 
hydrogen dioxid were found to be too unstable to keep for any length 
of time, and hence were unreliable. The problem of securing a stable 
high-percentage solution of the dioxid was solved by using ether as a 
menstruum, and the 25 per cent, solution of hydrogen dioxid made by 
McKesson & Robbins of New York and sold as " caustic pyrozone " 
is now generally used where hydrogen dioxid is employed as a bleaching 
agent in connection with discolored tooth structure. 

Hydrogen dioxid, H 2 2 , belongs to the class of " oxidizing bleach- 
ers," and owes its activity in this respect to the weak state of chemical 
combination in which one of its atoms of oxygen is bound to the water 
molecule. Many substances serve to disrupt the compound and liber- 
ate one of its oxygen atoms. In contact with pus, blood, inspissated 



BLEACHING BY HYDROGEN DIOXID. 551 

mucus, albumin, and in fact almost every kind of dead organic matter, 
its decomposition takes place, evolving oxygen and decomposing the 
organic matter either wholly or in part. Hydrogen dioxid does not 
bleach all of the decomposition-products of hemoglobin with equal 
facility. It quickly removes the pink discoloration following the initial 
extravasation of hemoglobin into the dentin, but when the brown stage 
has been reached indicative of the formation of hematin its action is but 
slight. Later, however, it bleaches more readily. The refractory 
nature of hematin with respect to hydrogen dioxid has been experimen- 
tally tested upon the substance out of the mouth. 

In bleaching discolored teeth with hydrogen dioxid the ethereal 25 
per cent, solution known as pyrozone is directly applied to the internal 
portions of the tooth upon small pledgets of cotton or cotton wisps 
rolled upon a fine flexible canal instrument. After each application 
the ethereal menstruum is evaporated by blasts of warmed air from a 
hot-air syringe, and the applications similarly made are repeated until 
the desired effect is produced. It has been found in practice that more 
rapid and permanent effects are produced when the pyrozone solution 
is rendered alkaline. This may be readily done by the addition of a 
few drops of liquor ammonia? fortior or by a solution of one of the 
caustic alkalies, e. g. sodium or potassium hydroxid or sodium dioxid. 
A very satisfactory method of securing the alkaline effect in this pro- 
cess is that suggested by Dr. D. N. McQuillen. His method is to 
first treat the pulp chamber and canals with applications of Schreier's 
Kalium-natrium preparation and after the debris from its action has 
been mechanically removed with instruments and cotton twists, with- 
out washing the canal, an application of pyrozone is made. The 
bleaching action follows with great rapidity, and has apparently greater 
permanence than where the pyrozone is used alone. In cases where 
the action proceeds very slowly, for example when at the end of a thirty 
minutes' continuous treatment the bleaching is not complete, it is well 
to seal an application of pyrozone upon cctton in the canal and allow it 
to remain for twenty-four hours, when a second treatment will usually 
complete the operation. 

In this as in all bleaching operations it is advisable to fill the tooth 
temporarily with some easily removable filling in order to test the per- 
manence of the operation, and after the lapse of a reasonable time if 
there is no tendency to a return of the discoloration the canals and 
cavity may be permanently filled. 

Dr. Harlan's method consists in acting upon hydrogen dioxid by 
aluminum chlorid. The aluminum salt is packed in the cavity and 
moistened with the dioxid. The technique of the procedure is the 
same as for the methods already described. This process was origin- 



552 DISCOLORED TEETH AND THEIR TREATMENT. 

ally classified with the chlorin methods, as the decomposition was sup- 
posed to take place according to the following equation : 

A1 2 C1 6 + 3H 2 2 = Al 2 O s + 3H 2 + 6C1. 

Experimental study of the reaction between aluminum chlorid and 
hydrogen dioxid by the writer developed the fact that oxygen and not 
chlorin was given off, and that the aluminum chlorid was unaltered 
during the process. Hence it was discovered that the reaction was 
simply due to a catalytic action of the aluminum salt (a property 
which in this relation it shares in common with many other metallic 
salts), whereby nascent oxygen is liberated from the hydrogen dioxid. 
The process, therefore, has no greater value than those in which hydro- 
gen dioxid is directly applied. The aluminum chlorid being an active 
coagulant is contraindicated as a factor in the bleaching process until 
a point has been reached where a coagulant is needed as a fixative after 
the bleaching has been effected. 

The Sodium Dioxid Method. — Sodium dioxid, Na 2 2 , is the chem- 
ical analogue of hydrogen dioxid, and like the latter is characterized 
by the readiness with which it parts with its atom of loosely com- 
bined oxygen under similar circumstances* The essential difference in 
its properties is the character of its by-product after its decomposition 
has taken place. Itself a strong caustic alkali, it still retains its alka- 
line and caustic properties after the loss of one of its atoms of oxygen, 
becoming Na 2 0, which in combination with water is ordinary sodium 
hydroxid or caustic soda. This substance as well as the sodium dioxid 
has not only a saponifying property for all of the vegetable and animal 
oils and fats, but also a solvent action upon animal tissue. This property 
is of great value in removing from the dentin structure all of the con- 
tained organic matter, whether normal or in a state of decomposition. 
Having the oxidizing and consequently the bleaching quality in addi- 
tion to its solvent and saponifying properties it is, therefore, one of the 
most valuable bleaching and detergent agents at our command. The 
substance is dispensed as a yellowish white powder in tin cans or 
glass bottles hermetically sealed, as it is very hygroscopic and after 
twenty-four hours' exposure to moist air absorbs nearly its own weight 
of water ; it also loses much of its activity. 

For use as a bleaching agent it is applied to the dentin in saturated 
solution. In making the solution especial care is necessary in order to 
avoid elevation of temperature, by reason of the energy with which it 
enters into combination with the water. If the solution is allowed 
to become heated in the making, decomposition of the compound with 
loss of oxygen occurs and its bleaching power is destroyed. The 



BLEACHING BY SODIUM DIOXID. 553 

solution is best made by pouring into a small beaker of about one 
ounce capacity about two drachms of distilled water, and immersing the 
beaker in a larger vessel or dish containing ice-water or pounded ice» 
The can containing the dioxid powder should then have its lid per- 
forated with a number of small holes similar to the lid of a pepper 
caster, and the powder be slowly dusted into the distilled water in the 
small beaker ; or the powder may be gradually dropped into the water 
by tapping it from the point of a knife or spatula. The powder is 
added to the water until the solution assumes a semi-opaque appearance, 
indicating the point of saturation. On removing the beaker from the 
cooling mixture, the dioxid solution will in a few minutes assume a 
transparent, straw-colored appearance and is ready for use. 

The applications are to be made similarly to the hydrogen dioxid 
applications, but upon asbestos fiber instead of cotton, as the latter is 
acted upon by the sodium dioxid and converted into a glue-like mate- 
rial, amyloid, which is difficult to remove and interferes with the suc- 
cess of the operation. 

After the dentin, which should have been previously desiccated, is 
thoroughly saturated with the dioxid solution an application of 10 per 
cent, sulfuric acid should be made, which neutralizes the strong alkali,, 
forming sodium sulfate and hydrogen dioxid, thus : 

]S T a 2 2 + H 2 SO, = NaJ30 4 + H 2 2 . 

The reaction is usually attended with some effervescence, which taking 
place in the tubular structure of the dentin, mechanically forces out its 
contents and thus exerts a detergent action upon it. The tooth should 
now be washed with hot distilled water in copious quantity and the 
dioxid application repeated, omitting the subsequent treatment with 
acid but washing again thoroughly with the hot water. 

Sodium dioxid solution, as prepared for bleaching, may be applied 
to the pulp chamber and root canal without the preliminary treatment 
required where other bleaching agents are employed. It is without 
harmful irritative action upon the apical tissues unless used in excess 
or forced through the foramen by careless manipulation. It is a power- 
ful germicide and disinfectant, and therefore peculiarly suited to the 
treatment of putrescent cases, which by its action are rendered sterile 
and aseptic as well as bleached at one operation. Its saponifying and 
solvent properties completely remove the greasy dark layer of decom- 
posed material which is found lining the pulp chamber and canals 
alluded to on page 546, so that the use of the sodium dioxid method 
makes unnecessary the application of borax or ammonia for its removal 
as a preliminary. When used for its sterilizing property the foramen 



554 DISCOLORED TEETH AND THEIR TREATMENT. 

should be allowed to remain unsealed until after the bleaching operation 
has been completed. It sometimes happens that the improvement in 
oolor following the application of the dioxid methods is only partial 
and the result falls short of restoration to normal ; or, in other words, 
the bleaching reaches a certain point beyond which the color resists the 
further action of the bleaching agent. In such cases the decomposition 
of the color molecule has probably resulted in the formation of iron 
oxid as an end-product. In practice this residual discoloration can 
generally be removed by treatment with oxalic acid. A small crystal 
is to be sealed in the moist pulp chamber for twenty-four hours, 
and afterward washed out with a copious irrigation of hot distilled 
water. 

The sodium dioxid method removes more completely than any 
other the tubular contents, and the result is unique from the fact 
that not only is the tooth restored to normal color but to normal 
translucency ; the opaque white effect resulting from other methods 
of bleaching is due to the bleached organic debris remaining in the 
tubuli, but by the solvent action of the strong caustic alkali this is 
removed. The final treatment of the tooth is the same in this as in 
other methods, though the dentin should be desiccated and saturated 
as thoroughly as possible with an unalterable varnish before the final 
filling is inserted. 

The Sulfurous Acid Method. — Reference has already been made 
to sulfurous acid as the single example of the reducing type of bleach- 
ing agent. Its activity is due to its affinity for oxygen, and it bleaches 
by seizing upon and combining with that element of the color molecule, 
thus destroying its identity and consequently its color. Attempts have 
been made to utilize the bleaching property of sulfurous acid in the 
treatment of discolored teeth by direct applications of the solution of the 
gas in water and by igniting small quantities of sulfur in the root canal 
by means of the electro-cautery wire. These methods have, however, 
proved inefficient. The gas may be successfully used in bleaching teeth 
by evolving it from its compounds placed in the cavity and root canal 
in a manner analogous to that employed in the Truman chlorin process 
already described. For this purpose the writer's method may be con- 
veniently employed : 100 grains of sodium sulfite and 70 grains of 
boric acid are separately desiccated and afterward ground together in 2 
warm dry mortar. The powder is then to be transferred to a tightly 
stoppered bottle. For bleaching purposes the powder is packed into the 
root canal and cavity of the tooth, and then moistened with a drop of 
water and the cavity immediately closed as tightly as possible with a 
stopping of gutta-percha previously prepared and warmed. A reaction 



CATAPHORIC BLEACHING OF TEETH. 555 

-ensues between the boric acid and sodium sulfite whereby sulfurous 
acid is liberated, thus : 

2H3BO3 + 3]Nra 2 S0 3 = 2]N T a 3 B0 3 + 3H 2 +3S0 2 . 

The process is effective in many cases where the chlorin methods have 
failed, but is slow in its action and is largely superseded by the dioxid- 
of -hydrogen and dioxid-of-sodium methods. 

Cataphoric Bleaching op Teeth. 

Since the revival of interest in cataphoresis and its application to 
dental operations its possibilities as an adjuvant in the tooth -bleaching 
process are being investigated with much promise of valuable results. 
It has been found that aqueous solutions of hydrogen dioxid may be car- 
ried into the dentinal structure with great ease by the cataphoric action 
of the continuous current. The appliances necessary for tooth-bleaching 
operations by this means are practically the same as those required in the 
treatment of hypersensitive dentin, and are detailed at length in the 
chapter dealing with that subject (page 189). The resistance offered by 
the hard structures of the tooth is much greater after loss of the tooth 
pulp, requiring a much higher voltage pressure to drive the bleaching 
agent into the tissue. While in some cases 25 to 30 volts will be all 
that is necessary, some cases will require as high as 60 volts to carry 
1.5 milliamperes of current through the dentin. The ethereal solution 
of hydrogen dioxid has been found to oppose too great resistance to 
the current, but the aqueous solution containing a slight addition of 
some salt to increase its conductivity is entirely manageable. 

A 25 per cent, aqueous solution of hydrogen dioxid may be quickly 
made by shaking together in a test tube one volume of water and two 
volumes of 25 per cent, pyrozone. The H 2 2 dissolves in the water, 
and the ether of the pyrozone may be removed by pouring the mixture 
into a small evaporating dish of porcelain or glass and gently heating it 
over a water bath until all of the ether has evaporated. The addition 
of a small quantity of sodium acetate or sulfate will greatly diminish 
the resistance of the solution to the passage of the current. 

With the tooth isolated by the rubber dam and having received the 
treatment preliminary to bleaching, as already described in detail, the 
aqueous solution of H 2 2 is dropped upon cotton within the tooth 
cavity and a platinum needle anode is applied in contact with it. 
The cathode may be a sponge electrode moistened with salt solution and 
held in the hand or applied to the cheek or neck. The hand, however, 
is preferable because of the amount of voltage required in the operation. 
Great care must be exercised that the external surfaces of the tooth are 



556 DISCOLORED TEETH AND THEIR TREATMENT. 

kept dry so that short-circuiting of the current may not take place. In 
some cases a more rapid effect is obtained by making contact of the 
cathode pole through a needle electrode upon the external surface of the 
tooth, and with the anode applied to the pyrozone solution on cotton 
within the tooth. The cotton must at all times be kept wet with the 
solution. 

The arrangement of the electrical terminals with respect to the 
bleaching operation is both theoretically and practically correct as de- 
scribed, viz. the flow of current should be from the anode point through 
the bleaching solution and tooth and the body of the patient to the 
cathode. In practice it has been found in some cases which have failed 
to bleach with the elements arranged in the series as stated, that upon 
reversing the poles and direction of current flow the bleaching has 
rapidly followed. The explanation of this apparent paradox is that 
by the application in normal order H 2 2 was first carried into the 
tubular structure, and the reversal of the current has acted upon the 
tubular contents now saturated with the dioxid, and by its propulsive 
as well as electrolytic effect removed the pigmentary matter pulp ward 
from the tubuli. Bleaching with reversed poles would be impossible 
without previous saturation of the dentin by the dioxid solution. 

Dr. M. W. Hollingsworth has devised an ingenious anode for feed- 
ing the bleaching solution or other medicament into the cavity as de- 
sired. The instrument (Fig. 154) is described in Chapter VII. 

Another device by Dr. Hollingsworth is of especial value, as it 
makes possible the enveloping of the entire tooth with the bleaching 
fluid in which it is immersed as in a bath. The appliance is shown in 

Fig. 481. 




Dr. Hollingsworth's device for applying the bleaching agent to the tooth. 

situ in Fig. 481, and consists of a thin vulcanized caoutchouc bulb 
shaped like the bulb of a medicine dropper. Through a perforation 
at its rounded end made with the ordinary rubber dam punch, the 
tooth is slipped by mounting the bulb on the applicator (Fig. 482), and 



CATAPHORIC BLEACHING OF TEETH. 557 

forcing it over the tooth as though it were a rubber dam. A glass tube 

Fig. 482. 




Applicator. 



is then attached to the open end of the bulb, and to the glass tube is 
connected a spiral platinum wire electrode (Fig. 483). Before the elec- 



Fig. 483. 




Tube electrode. 



trode is attached the bulb and glass tube are completely filled with the 
aqueous pyrozone solution by means of a duplex syringe (Fig. 484), the 



Fig. 484. 




Duplex syringe. 



lower and larger bulb of which exhausts the contained air in the appa- 
ratus and the smaller thumb bulb injects the bleaching solution into the 
exhausted apparatus. Connection is now made with the source of cur- 



558 DISCOLORED TEETH AND THEIR TREATMENT. 

rent as usual, and the bleaching is very rapidly effected. Dr. Hol- 
lingsworth recommends the addition of about 1 per cent, of zinc sulfate 
to the aqueous pyrozone solution, which not only diminishes the resist- 
ance to the passage of the current, but has a coagulating effect upon 
the bleached organic matter which gives it translucency and greatly 
enhances the permanency of the operation. The results obtained by 
this method are extremely satisfactory. 

Bleaching Methods for Special Stains. 

Pulpless teeth are especially liable to discoloration from external and 
accidental causes. If decayed and the cavity has remained unfilled for 
a length of time many substances which find their way into the oral 
cavity either as food or as medicine may produce discoloration when 
absorbed by the tooth through the open cavity walls. 

Metallic salts are particularly apt to cause such staining by reaction 
with the sulfids with which the dentin structure is usually saturated 
during decomposition of its organic contents. Many of the medica- 
ments used in pulp-canal treatment or even for hypersensitive dentin 
may stain the tooth structure, and finally the action of sulfids in the 
structure of a pulpless tooth may react with amalgam fillings, forming 
salts of mercury^ silver, tin, copper, etc., which are absorbed by the 
tooth, resulting in its discoloration. The treatment of these stains, 
which were grouped as Class III. at the beginning of this chapter, 
is extremely difficult and often unsatisfactory. However, there may 
arise individual cases of discolorations of this class where it is of the 
utmost importance to remove them, and much may often be accom- 
plished when the causes of the discoloration are known and the proper 
bleaching method is applied. 

Gold stains may arise, as has been already indicated, from the inju- 
dicious use of gold instruments or failure to remove all gold fillings 
when applying some one of the chlorin methods of bleaching. In the 
course of time where this has happened the tooth assumes a pinkish 
hue which merges into a characteristic violet or purple, finally becom- 
ing black. 

Iron stains may arise from the use of steel instruments in connection 
with the chlorin methods of bleaching or in contact with iodin or any 
of the mineral acids in connection with canal treatment. The iron 
stain is yellowish at first, gradually becoming brown and finally black. 

Cojyper and nickel stains may arise from contact with these metals 
or their alloys, as copper amalgam or nickel or German silver 
dowels for artificial crowns or anchorages for fillings. The stains 
from these metals are — for copper, bluish to black, and for nickel a 
characteristic chlorophyll green which eventually becomes black. 



BLEACHING METHODS FOR SPECIAL STAINS. 559 

The best general treatment for all of the foregoing stains is to 
re-bleach the tooth by the chlorin method, with especial care as to the 
several precautions already recommended, and when the color of the 
metallic stain has been discharged by conversion of the dark-colored 
salt into a soluble chlorid, wash the tooth thoroughly first with dilute 
chlorin water 50 per cent., and afterward with hot distilled water to 
remove all of the metallic chlorid which has been formed. The process 
may require repetition to secure permanent results. 

Silver stains are comparatively easy to remove, either by an applica- 
tion of the chlorin method or by saturating the tooth with tincture of 
iodin, thus converting the silver salt into a chlorid or iodid as the case 
may be, after which it may be dissolved out with a saturated solution 
of sodium hyposulfite applied as a bath to the tooth. For this pur- 
pose the Hollings worth bulb dam (see Fig. 483) answers admirably, 
and although the experiment has not as yet been tried, there is good 
reason to believe that the cataphoric method with electrodes applied in 
reverse order would under these circumstances greatly facilitate the 
solution and removal of the metallic salts. 

Mercurial stains are always black from the formation of mercuric 
sulfid, and are removable by the same method as are silver stains, with 
the exception that where the stain has been converted into a chlorid 
by the chlorin method, the mercuric chlorid is best removed by an 
aqueous ammoniacal solution of hydrogen dioxid, or Avhen the stain 
has been converted into mercuric iodid by the use of a saturated solu- 
tion of potassium iodid. In both cases a final washing with hot dis- 
tilled water is a sine qua non. 

Manganese stains frequently occur from the use of potassium per- 
manganate, in solution or in substance, in the treatment of putrescent 
canal conditions. The manganese stain is a characteristic mahogany 
brown. It is very readily removed by a 25 per cent, aqueous solution 
of hydrogen dioxid in which oxalic acid crystals have been dissolved 
to saturation. A few applications of this mixture will quickly de- 
colorize the stain, after which a liberal treatment of hot distilled water 
is required as in the foregoing cases. 

In all cases a careful diagnosis of the chemical nature of the dis- 
coloration should be made when possible. Much information upon this 
point may be gained by a detailed study of the present condition of the 
tooth and its environment, but in addition to this the patient should be 
questioned as to the history of the case, and especially as to its previous 
treatment. The data thus obtained should be carefully noted and treat- 
ment instituted in accordance with the conditions to be met. 

Success in the bleaching of teeth demands a recognition of the fact 
that each case presents individual peculiarities, that the problem is 



560 DISCOLORED TEETH AND THEIR TREATMENT. 

essentially a chemical one always, and that the bleaching method in any 
given case must be selected with especial reference to the character of 
the discoloration and applied with due care as to its details in order that 
the chemical requirements of the operation may be intelligently met ; 
without which care success is impossible. 



CHAPTER XXI. 

EXTRACTION OF TEETH. 

By M. H. Cryer, M. D., D. D. S. 



Indications for the Operation. 

It is impossible to formulate a set of exact rules by which the prac- 
titioner may be governed, in deciding upon the extraction of teeth. So 
many circumstances both local and general must be taken into consid- 
eration that little more can be done than to suggest the most important 
causes which demand the operation. 

Deciduous Teeth. — The indications for extracting deciduous teeth 
are — 

First : When the teeth are a source of irritation affecting the gen- 
eral health or comfort of the child and do not respond to treatment. 

Second : When the deciduous teeth are preventing the eruption of 
the permanent teeth into their normal positions. Occasionally a de- 
ciduous tooth will assist in the proper placing of a permanent one, 
in which case it should not be removed as long as it is of such 
use. 

Third : When a lower permanent incisor shows signs of erupting on 
the labial side of the deciduous tooth, the latter should be removed at 
once, but if the erupting tooth appears on the lingual side the removal 
of the deciduous tooth may in that case be delayed somewhat longer. 

Fourth : When upper permanent incisors show a tendency to erupt 
on the palatal side of the temporary teeth, the latter should be extracted, 
but when they are erupting on the labial side the deciduous teeth may 
be allowed to remain for a time, as they are often useful in forcing the 
permanent teeth outwardly. This, however, must be closely watched 
to prevent the permanent incisors from moving too far. 

Permanent Teeth. — The indications for extraction of the permanent 
teeth are — 

First : Diseased roots which cannot be cured and so made useful 
for crowning, or assisting in retaining a bridge, plate, or other pros- 
thetic device. 

36 561 



562 EXTRACTION OF TEETH. 

Second : Teeth of mastication that have lost their occluding teeth 
and in consequence thereof are being pushed from their alveoli and are 
a source of trouble. As a rule, this refers only to the second or third 
molars, and more particularly to the third molar. When it occurs with 
other teeth the opposite vacant space should be filled by an artificial 
tooth to prevent the extrusion of the natural tooth. 

Third : When incurable abscesses originating from teeth in the 
upper jaw tend to open into the nasal chamber, maxillary sinus, or 
zygomatic fossa, the teeth associated with such abscesses should be ex- 
tracted. When diseased teeth are the exciting cause of an incurable ab- 
scess in the lower jaw which opens or threatens to open externally on 
the chin, jaw, or below the bone into or upon the neck, they should be 
removed. 

Fourth : Teeth which occupy irregular positions in the arch, that 
cannot be corrected so as to become useful or contribute to the gen- 
eral symmetry of the mouth, should be removed. 

Fifth : Erupting teeth that are retarded because of lack of room 
in the jaw, if giving pain, should be extracted or else the tooth that is 
preventing the eruption should be removed. A marked example of 
this is often found in the eruption of the third molar when all the other 
teeth are of good size and are in place. These molars when retarded 
cause the greatest distress, sometimes producing serious results, and 
must be extracted ; if they cannot be safely removed the second molar 
may be extracted, in consequence of which the third molar will usually 
be erupted near its place. When an upper third molar is erupting 
under the same circumstances there is usually less difficulty, as having 
but slight resistance distally it can erupt outwardly or slightly back- 
ward, though, should it impinge upon the soft tissues covering the ramus 
of the lower jaw, it should be extracted. 

Sixth : Teeth so badly diseased that they will not respond to treat- 
ment and are a source of discomfort to the patient should be removed, 
as they impair the general health. 

Seventh : First molars. There has been much discussion regarding 
the early extraction of these teeth, many claiming that if the pulp of 
one becomes devitalized at an early period of life and it is deemed best 
to extract it, the other three should also be removed. No fixed general 
rule, however, can be given ; each case must be considered separately. 
There are cases where the extraction of all is necessary, and others 
where it would be a most unwise thing to do. When the anterior teeth 
are fully in position, the bicuspids occluding correctly with their oc- 
cluding teeth and the second molars are about to erupt, the case may 
then be one for extracting the four first molars, provided it be neces- 
sary to extract one of them, or if it be likely that one or more of them 



INDICATIONS FOR THE OPERATION. 563 

will be lost in a few years. If, however, the bicuspids are not in good 
position, it is better not to extract the first molars, as they assist in keep- 
ing the jaws the proper distance apart, and preventing the lower anterior 
teeth from biting against the upper gum. 

Removal of Sound Teeth Preparatory to Inserting- Artificial 
Dentures. — When preparing the mouth for an artificial denture the 
removal of sound teeth may be indicated as a measure of expedi- 
encv in relation to mechanical and hygienic considerations. For ex- 
ample : 

(1) Roots which a plate or bridge would cover, excepting when they 
assist in holding the device. 

(2) Teeth from which the gums have receded to such an extent as 
to become useless or unsightly. 

(3) Teeth that are being extruded from their alveoli from the ab- 
sence of occluding teeth. The extraction of these depends, however, 
on the extent of " elevation " and the possibility of placing occluding 
artificial teeth in position. 

(4) Where there is but one tooth remaining, or two teeth standing 
together, or in certain cases when several isolated teeth remain which 
cannot be made to contribute to the mechanical adaptation of an arti- 
ficial denture, extract when in the upper jaw. They interfere with the 
fitting of an upper plate, but in the lower jaw they may be useful in 
retaining the plate. 

(5) When there are two teeth, one on each side of the upper jaw, in 
good position and desirable shape for clasping, do not extract unless 
they are the third molars or the oral teeth. 

(6) In preparing the upper jaw when two canine teeth alone remain, 
or when there is also a molar or bicuspid, or both, and it is decided to 
extract the molars and bicuspids, then extract the two canine teeth also. 
It has been claimed by some of the very best dental practitioners, whose 
opinions must be respected, that by keeping these teeth the expression 
of the face is less likely to be marred. For the following combined 
reasons, however, extraction is advised : 

a. It is very difficult to obtain a correct impression of the mouth 
while these teeth only are in position. 

b. It is nearly impossible to perfectly match, grind, and arrange the 
lateral incisors beside single canines. 

c. The adhesion of the plate to the mouth is interfered with, as air 
and food work in between the plate and these natural teeth. 

d. The plate is very much weakened by being cut out for the accom- 
modation of these teeth at what might be termed the abutments of the 
arch. 

In the lower jaw single teeth which are sound are usually of great 



564 EXTRACTION OF TEETH. 

importance. They should not be removed, as they assist in retaining 
a denture by means of clasps or other devices. Especially is this true 
in persons advanced in years, as then the alveolar process is generally 
much absorbed. If the lower process is much absorbed even an imper- 
fect tooth will do good service of this character for a time, and if it is 
the first plate the patient has worn it will serve a good purpose by 
assisting in the retention of the plate until the patient has become ac- 
customed to it, after which the tooth, if giving trouble or if it is un- 
sightly, may be removed and an artificial one placed on the plate. 

Instruments and Accessories for Extracting. 

The instruments used in extracting teeth are forceps and elevators 
of various shapes and sizes. 

Forceps. — The forceps should be made of steel of the best quality 
for the purpose obtainable, in order to give great strength and stiffness, 
and at the same time toughness, so that they will not break. Forceps 
that will spring or bend destroy the sensitivity of the hand using them 
in such a way as to prevent the operator from discerning in what di- 
rection the resistance to extraction is being made. The beaks of the 
forceps as a general principle should be shaped so as to fit and adjust 
themselves to as great a surface of the various teeth or roots as pos- 
sible so that they may take a firm hold. They should be at such an 
angle in relation to the handles as will permit them to be easily and 
readily placed in the proper position without obscuring the view of the 
tooth to be extracted. The inner surface of each beak should be concave 
in a transverse section and without serrations, as these are of no assist- 
ance, but tend to weaken the beaks and are difficult to clean. The edges 
of the concave portion should be sharp enough to cut through the alveolar 
process if necessary. The points of the beaks should be sharp and 
tapering so they can be forced into position. The handles should be of 
a shape to allow a firm grasp, and as the hands of different operators 
vary in shape and size it will be evident that the same size of forceps 
handles will not be perfectly satisfactory to all. The curvature of the 
handles should vary according to the general or special use of the for- 
ceps. The curved ends, as seen in Fig. 485, are of little use, and should 
be done away with in all forceps excepting perhaps those made especially 
for the upper and lower molars. 

The joints of extracting instruments should be so made that the 
handles can be separated by some simple mechanism to permit of 
thorough and easy cleansing. Figs. 485 and 486 represent an instru- 
ment of this character. There are others of the same nature, but 



INSTRUMENTS AND ACCESSORIES EOR EXTRACTING. 



565 



Fig. 485. 




this being the most simple and 
the strongest should be gen- 
erally adopted unless a similar 
device can be adapted to the 
" knuckle-jointed " instrument. 
(Fig. 487.) 

There should be no sharp 
angles or crevices, and if the 
ordinary forceps is used, that 
portion around the joint in a 
transverse section should be oval. 
Forceps are often made with 
octagonal joints, but these should 
be condemned, as they may 
not only hurt the lips of the 
patient, but in case of a slip, 
which may happen with the best 
operators, they are more liable to 
cause injury by striking the other 
teeth ; moreover they are very 
clumsy and require more room. 

Fig. 486. 




Antiseptic universal lower molar forceps. 



Joint of an antiseptic lower molar forceps 



566 



EXTRACTION OF TEETH. 



Fig. 487. 



Unless the antiseptic joint 
(Figs. 485 and 486) is used the 
union of the joints is usually 
made upon one of two principles : 
first, by one half passing into a 
mortise in the other and held in 
the centre by a pinion (Fig. 488). 
The second is known as a 
knuckle-joint (Fig. 487) made 
by each portion being let half 
way into the other and held to- 
gether by a screw. This is a 
neater joint and does away with 
many of the objectionable fea- 
tures noted in other forms of 
forceps joint. 

All handles should be ser- 
rated as shown in the illustra- 
tions, and the instruments if 
properly cared for need not be 
nickel-plated. The number of 
forceps in a practical set will 
vary with the requirements of 
every individual who extracts 
teeth, therefore only the general 
principles which should govern 
the selection of a set of instru- 
ments will be here given ; at the 
same time the uselessness of a 
very large selection is here em- 
phasized. As an illustration of 
the range of tooth extractions 
which may be performed with a 
limited number of instruments 
the forceps represented by Figs. 
488 and 489, showing the exact 
size, will serve as examples. 
They are smaller than the ones 
generally used, especially in 
America. 

The instrument shown in Fig. 
488 may be used almost universally for the upper teeth. 

Fig. 489 is a forceps of the same general character as that in Fig. 




Knuckle-joint root forceps. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING. 567 
488, only the beaks are at a different angle with the handles. This pair 



Fig. 488. 



Fig. 489. 






at 



m 

ami 






Universal upper incisor and root forceps. 



Universal lower incisor and root forceps. 



may be used similarly for the lower teeth. These forceps are useful in 
all cases, except in the full arch, when either a first or second molar is 



568 



EXTRACTION OF TEETH. 

Fig. 490. Fig. 491. 




m 



For the ten upper anteiior teeth 



Root, upper front. Straight. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING. 569 



Fig. 492. 



to be extracted. If the teeth are large, the jaw strong, and the 
grinding surfaces concave, it is 
better to use the special lower 
molar forceps as shown in Figs. 
485 and 498. 

Fig. 490 and Fig. 491 rep- 
resent very useful forceps for 
extracting the ten upper an- 
terior teeth. Fig. 491 has 
longer beaks and its points are 
finer. In skillful hands where 
too great a force will not be 
brought to bear on the points 
they are the better forceps. 
Under nitrous oxid and where 
many teeth are to be extracted, 
thus requiring rapid work, the 
instrument shown in Fig. 490 
is preferable. 

Figs. 492 and 493, right and 
left, represent forceps specially 
used for extracting the first and 
second upper molars on either 
side. The outer beak is made 
pointed for the purpose of pass- 
ing in between the buccal roots, 
the inner beak is concave in 
order to grasp the palatal root. 
Figs.495and 496 show bayonet- 
shaped forceps, that illustrated 
by Fig. 495 being especially 
made for extracting the upper 
third molars, Fig. 496 being 
used for upper roots. The ends 
of the handles of all forceps 
which are forced in by the palm 
of the hand should have abroad 
surface as shown in Fig. 496. 
These forceps are popular with 
many operators. The writer 
considers them clumsy, as they 
obscure the proper view of the 
tooth and its associated parts. 



line of 




Right upper molar. 



570 



EXTRACTION OF TEETH. 



Fig. 493. 



Fig. 494. 




Left upper molar 



Hawk-beaked forceps. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING. 571 
Fig. 495. Fig. 496. 







& 



W 



Universal upper third molar. 



Dorr's upper root forceps. 



572 



EXTRACTION OF TEETH. 



Fjg. 497. 



Fig. 498. 




Universal lower canines and bicuspids. 



Universal lower molars, designed by Dr. 
Chapin A. Harris. 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING. 573 
Fig. 499. 



Fig. 501. 




Root, lower. Half curved. 



Elevator. 



Right and left scalers 
used for extracting 
roots. 



574 EXTRACTION OF TEETH. 

Forceps for Extracting Lower Teeth. — Instead of the beaks of the 
forceps being nearly on a line with the handles as in those for the upper 
jaw, they are bent at nearly a right angle. For the incisors of the lower 
jaw there are no better forceps than those shown in Fig. 489. This 
instrument is very useful in extracting the lower third molar when fix- 
ation of the jaw from diffuse cellulitis in the region of the temporo- 
maxillary articulation renders it difficult to open the mouth sufficiently 
for inserting a larger instrument. In such cases the forceps should be 
carried backward in the vestibule of the mouth with the inner beak 
passing between the upper and lower teeth ; when the beaks reach the 
third molar the inner beak can usually be forced over the inner surface 
of the tooth and into position, after which the tooth can be grasped 
and extracted. The forceps represented in Fig. 488 can also be used 
to advantage for these teeth, the operator standing behind and working 
over the head of the patient, as shown in Fig. 546. 

Fig. 494 exhibits a hawk-beaked forceps for extracting the anterior 
lower teeth. It is very popular with some operators, especially those 
in Europe. The writer does not recommend it. 

Fig. 497 also exhibits a special instrument. It is made for extract- 
ing the lower canine and bicuspid teeth of either side. Fig. 498 is a 
special instrument used for the lower molars of either side. The beaks 
are pointed, with a convexity on each side of the point to allow it to 
pass in between the roots. The two concave portions fit against each 
root. 

Fig. 499 represents a universal lower root forceps. 

Elevators or Root Extractors. — There are many kinds of 
elevators used in extracting roots. Some are also occasionally used in 
the extraction of teeth (usually the third molar). 

Fig. 500 shows one of the most useful forms of this instrument. It 
is especially useful in extracting third molars when the teeth in front 
of them are in position. 

Fig. 501 represents two elevators ; they are similar to right and 
left scalers, being made somewhat heavier; they are extremely use- 
ful in extracting roots. They are so unlike an extracting instru- 
ment that patients do not dread the appearance of them as they do 
that of forceps. By carefully inserting the blade with the point 
toward the root to be removed, between it and the adjoining root or 
tooth, and giving a slight rotary motion, the point will force the root 
from its socket with but little pain. 

Figs. 537 and 538 illustrate two other forms of elevator, with their 
mode of application in the removal of roots. 

Lancets. — Figs. 502 and 503 represent various forms of lancets, 
the more useful of which are Nos. 1 and 5, which are all that are 



INSTRUMENTS AND ACCESSORIES FOR EXTRACTING. 575 

required for lancing in extracting or for relief of retarded eruption of 

deciduous or other teeth. They are also useful in general surgery of the 

mouth. The handles should be made of metal instead 

502, of wood, in order that they may be thoroughly sterilized. 

Fig. 503. 




Lancets with ebony handles and with solid steel handles. 

Scissors. — A good pair of curved scissors, as shown 
in Fig. 504, should be at hand in case a portion of 
gum tissue is found to be attached to the root. If the 
scissors were slightly more curved they would be even 
better adapted for this purpose. 

In connection with the instruments already men- 
tioned, there should be a mouth mirror (Fig. 505) 
and a few excavators and probes for general exami- 
nation of the teeth, especially for examining the position 
and character of a root or impacted tooth which it is 
purposed to extract. 

Mouth Props. — When an anesthetic is to be given 
it is advisable to use some kind of a mouth prop, in 
order to keep the mouth well open. Some operators do 
not use them, as they may interfere with the giving of 
the anesthetic by impeding respiration upon beginning 
the administration. The majority of patients, if asked 
to hold the mouth open while taking the anesthetic, 
especially nitrous oxid and oxygen, will keep it open 
during the anesthetic stage. 
Fig. 506 illustrates excellent props devised by Dr. Frederic Hewitt, 
of London, England. 



576 



EXTRACTION OF TEETH. 



Fig. 504. 



The Mechanical Mouth-opener (Fig. 507). — This instrument 
is made in various shapes and sizes. It is inserted between the jaws 
when the props are to be removed or in eases of trismus, and may also 
be used to separate the jaws and retain them so in eases of emergency 
or during certain operations within the oral cavity. 

All dentists, and especially those 
who extract teeth, should have at 
least one pair of pharyngeal for- 
ceps (Fig. 508). It is possible that 
they may never be used, but on the 
other hand an accident may occur 
such as a fragment or tooth slip- 
ping into the pharynx, where if the 
finger cannot reach it this instru- 
ment will be absolutely necessary. 
Surgical Anatomy. — To extract 
teeth successfully it is first neces- 
sary to be perfectly familiar with 
the general shapes of the different 

Fig. 505. 





Curved scissors. 



Mouth mirror. 



teeth and their position in relation to the jaw and to their associates, in 
order that the operator may intelligently apply the force in the line of 
the least resistance required for their removal. This knowledge cannot 
be obtained from books ; they are but the guides to it. The jaws of the 
dead subject must be dissected — both the cleaned bones and those with 
the soft tissues left upon them. " Dissection " means that not only 
shall the superficial relations be studied, but that the bones shall be cut 
in various directions, both with the saw and other instruments, until 



SURGICAL ANATOMY. 



577 



the relations of the teeth of the upper jaw with the floor of the nasal 

chamber and the maxillary sinus are fully understood. In the lower 

jaw the relations of the teeth with the inferior dental canal and the 

position of the roots, especially those of the third molar, must also be 

thoroughly known. 

Fig. 506. 




Hewitt's mouth props (half size). 

The alveolar process of both jaws is made up of two plates, external 
and internal, consisting of dense compact bone without a true line of de- 

Fig. 507. 




Mechanical mouth-opener (half size). 



markation between the process and maxilla proper. The interspaces be- 
tween these plates formthe sockets for the teeth and are surrounded by a 



Fig. 508. 




Pharyngeal forceps (half size). 



very thin cribriform plate of cortical bone. The remaining space is filled 
with cancellated tissue, small bony channels, connective tissue, nerves, 

37 



578 



EXTRACTION OF TEETH. 



vessels, etc. As this process belongs to the teeth, being developed with 
them, and is for the purpose of holding them in position, it disappears to 
a greater or less extent when the teeth are lost. The resorption of this 
process does not take place alike in each jaw. In the upper jaw the 
external plate disappears more rapidly and to a greater extent than 
the inner plate ; in the lower jaw the resorption of the two plates is 
about equal in extent and rate. The inner plate of the upper jaw is 
partially supported by the external plate of the palatal process, in fact 
one merges into the other. The outer alveolar plate of the upper jaw 
being resorbed to a greater extent than the inner one is of advantage 
to the dentist in fitting teeth to the gums ; consequently, in extrac- 
tion that fact should be remembered and injury to the internal plate 
avoided. At the same time it does no harm to remove a small por- 
tion of the outer plate, though loss of the gum tissue should be 
avoided if possible. In the lower jaw it is not so important to avoid 



Fig. 509. 




Alveoli of permanent teeth— upper jaw. 

removing slight portions of the inner plate, as resorption takes place 
about equally in the two plates. 

These plates may be resorbed in such a manner that a slight ridge 
is left between the places which they occupied. This resorption of 
both plates of the alveolar process of the lower jaw makes it more diffi- 
cult to fit single plain teeth in the lower than in the upper jaw. 



SURGICAL ANATOMY. 
Fig. 510. 



579 




Alveoli of permanent teeth— lower jaw. 

Fig. 509 shows the alveoli of the upper denture, Fig. 510 that of 

the lower. 

Fig. 511. 




Typical upper and lower jaw. 

Fig. 511 illustrates a typical upper and lower jaw, the external sur- 



580 



EXTRACTION OF TEETH. 



faces of the crowns of the teeth, also a normal occlusion. Figs. 512 
and 513 illustrate the occluding surfaces of the teeth and their relations 
with each other. They are made from the same skull as Fig. 511. 



Fig. 512. 




Showing the occlusal surfaces of the upper teeth. (From same skull as Fig. 511.) 

Fig. 514 is from a photograph taken from the right side of a skull. 
It gives a good representation of a fairly normal occlusion of the 

Fig. 513. 





9 



Showing occlusal surfaces of the lower teeth. (From same skull as Fig. 511.) 



teeth, their shape, roots, and their relation with the cancellated tissue 
and the inferior dental canal or cribriform tube of the lower maxilla. 



SURGICAL ANATOMY. 
Fig. 514 



581 







Showing the buccal surfaces of the crowns and roots in position. 
Fig. 5 15. 




From the same jaw as Fig. 514.) 



582 



EXTRACTION OF TEETH. 



In the upper jaw the bone is thin over the position of the molar teeth, 
and their roots are comparatively straight; none of these should be 
difficult to extract. The buccal roots of the first molar are somewhat 
divergent from each other. The same roots of the second molar spread 
only slightly as they leave the crown and close in at the points. The 

Fig. 516. 

Hs ' Mec 




T Ns Hp 
Hs, Hiatus semilunaris; Mec, middle ethmoidal cells; CI, crystalline lenses; Up, uncinate pro- 
cess ; Mt, middle turbinated bone ; Mm, middle meatus ; Ms, maxillary sinus ; Im, inferior 
meatus ; It, inferior turbinated bone ; V?n, vestibule of mouth ; 1st M, first molar ; Dis. r. 1st M, 
distal root first molar ; Idn, inferior dental nerve ; T, tongue ; Ns, nasal septum ; Hp, hard 
palate. 

roots of the third molar are together and slightly curved backward. In 
the lower jaw the roots are comparatively straight. Those of the first 
molar are spread only a little apart, this being the usual condition. 
The roots of the second molar are almost straight and are nearly parallel 
with each other. The anterior root of the third molar curves slightly 
backward until it joins the posterior root. 

Fig. 515 is taken from the left side of the same jaw as Fig. 514. In 
Fig. 514 the roots have been exposed down to their apices ; in Fig. 515 
only the external or cortical plate has been removed. These two illus- 



SURGICAL ANATOMY. 



583 



trations give a correct idea of the relations of the teeth to the internal 
structures of the jaw. 

Figs. 516 and 517 are good illustrations of the relations of the roots 



Fig. 51" 



Oms 




Oms 



1st M 1st M 

Oms, Opening maxillary sinus ; 1st M, first molar. 

with the floor of the maxillary sinus usually found in the white race. 
In the negro there is usually a considerable thickness between the 
teeth and the floor of the sinus. It will be noticed that the roots of 
the molars pass up on both sides of the sinus, and because of this fact 
it is necessary in extracting teeth from a jaw of this character to use 

Fig. 518. 







Ar 1st M, Anterior root of first molar; E 2d Bi, root of second bicuspid; Idn, inferior dental 
nerve ; U, U-shaped or cortical portion of lower jaw. 

the greatest caution, otherwise a portion of the floor of that cavity might 
also be removed. Or if a tooth be broken and much upward force used 



584 



EXTRACTION OF TEETH. 



in endeavoring to take hold of the root, the latter could easily be forced 
into the sinus. The lower portion of Fig. 516 gives a general idea 
of a transverse section of the lower jaw made posterior to the mental 
foramen. Especial attention is drawn to the U-shaped formation of 
the cortical portion of the lower jaw which terminates in the two plates 
of the alveolar process, and between which the roots are imbedded in 
the cancellated tissue. It also shows how the roots extend toward the 
inferior dental nerve. There is no line of demarkation between the 
alveolar process and the body of the bone. 

Fig. 518 shows the relation, length, and position of the second bicus- 



Fig. 519. 




pid, showing that its root is sometimes placed to the inner side of the 
anterior root of the first molar. The roots of these bicuspids are flat, as 
will be seen by looking at Fig. 533. On taking into consideration their 



SURGTCAL ANATOMY. 



585 



length, position, and thinness it will be readily seen why it is so often 
difficult to extract them without breaking. 

Fig. 519 is taken from horizontal sections of the lower and upper 
jaws, showing the transverse sections of the roots of the teeth. The 
section is made a little above the margin of the alveolar process of the 
upper jaw and a little below in the lower. The illustration shows the 
shape and position of the various roots, with their relations to the pro- 
cess and to each other. Particular attention should be given to the fact 



Fig. 520. 




RSdBi 



R 1st Bi 



Re Rli 

Dn, Dental nerve ; R 3d M, roots of third molar; R 2d M, roots of second molar; R 1st M, distal 
root of first molar; R 2d Bi, root of second bicuspid; R 1st Bi, root of first bicuspid; Re, 
root of canine ; Rli, root of right lateral incisor. 

that the roots and process are in such close relation as to make it im- 
possible to force the beak of a forceps between them without breaking 
one or both plates of the process. The lines leading from the roots 
show the proper direction for applying what is known in extracting 
as the u out-and-in motion. " 

Fig. 520 represents a horizontal section made through the lower jaw 
near the ends of the roots, and from the same bone as that shown in the 
lower half of Fig. 519. The cancellated portion with the soft tissue 
filling the spaces can be plainly seen. The nerve passing into its tube, 
the ends of the roots of the second and third molars, the tip of one of 



586 



EXTRACTION OF TEETH. 



the roots of the first molar, and the roots of the first and second bicus- 
pids are all plainly shown. A little of the lateral incisor can be noticed, 
but the centrals do not reach so far down. 

Figs. 521 and 522 are taken from a sagittal section of the upper 
jaw, external to the infraorbital foramen, and through the roots of the 

Ftg. 522. 




-" 



- jf* 



— Om 




Ifs, Infraorbital sinus ; If, infraorbital foramen ; 
Pic, piece of paper passing through infraorbital 
canal ; Ms, maxillary sinus ; Aa, apical abscess. 



Om, Opening into malar bone : 
Ifs, infraorbital sinus. 



molar teeth. This illustration shows how the roots often extend above 
the lower portions of the floor of the sinus, an abscess from the palatal 
root of the first molar having discharged into the floor of the sinus 
at the point Aa. 

It has been demonstrated both anatomically and clinically that in- 
fectious matter from a suppurating tooth may eventually give rise to an 
inflammation of the meninges of the brain. Should pus from a dento- 
alveolar abscess discharge into the maxillary sinus it may pass out into 
the hiatus semilunaris and ascend into the frontal sinus or in the vicin- 
ity of the cribriform plate of the ethmoid through the infundibulum when 
the passage through the hiatus into the middle meatus is small or con- 
stricted, as it usually is when inflamed, or the pus may pass directly 
through the infundibulum. Recent research has shown that the frontal 
sinus, the cribriform plate of the ethmoid, and the meninges of the brain 
are in close relation at the anterior portion of the cribriform plate, a dis- 
eased condition at which point is liable to involve all three structures. 

Fig. 523 is from a longitudinal section of the lower jaw, and gives a 
good idea of the cancellated tissue, the relations of the sockets of the 
teeth to one another, and the position of the inferior dental canal. 



SURGICAL ANATOMY. 
Fig. 523. 



587 




Fig. 524. 




• ^ 








4 





II 




588 



EXTRACTION OF TEETH. 



Fig. 524 is taken from several transverse sections of a lower jaw. 
The bone is not quite normal, as several teeth were extracted before 
death, the loss having caused changes in the character of the bone. 
Some of the sections show but one canal while in others there are many, 
requiring close observation to tell in which the nerves and vessels have 
passed. At point D it will be seen that the root of the second molar 
penetrates the true nerve canal. 

Fig. 525. 




Fig. 525 is taken from the inner side of the right half of a lower 
jaw. The second molar has been broken off, the roots still remaining 



Fig. 526. 




in position. The points of the roots of the third molar pass out through 
the inner wall a considerable distance below the mylo-hyoid ridge. A 



SURGICAL ANATOMY. 



589 



portion of the ridge has been cut away, exposing the remainder of the 
internal surface of the roots. This will be further alluded to when ex- 
traction of the lower third molar is considered. 

Figs. 526 and 527 are from the outer side of the right half of a lower 

Fig. 527. 




jaw, Fig. 526 showing an impacted third molar lying horizontally in 
the jaw. Fig. 527 is of the same jaw with the tooth removed from its 
bed, showing the inner surface. The second molar is a pulpless tooth 
the distal root of which shows where the impacted tooth has pressed 
against it, causing the absorption of a portion of the root and exposing 
the pulp canal within, producing death of that organ. This must have 
caused neuralgia. The cancellated tissue of this bone, it will be noticed, 
is not like that •shown in Fig. 512, the change in the character of this 
tissue being the result of irritation caused by the impacted tooth. It 
will be seen that the roots of the other teeth in this jaw are longer 
than usual, the canine tooth passing below the nerve and to the outer 
side. 

Figs. 528 and 529 represent the inner side of the left half of a lower 
jaw. It shows an impacted third molar pointing slightly downward. 
The distal root of the second molar is slightly absorbed. On uncover- 
ing the tooth and taking it from its bed, it was found to be incased in a 
thin shell of bone as though the dental sac had ossified separately around 
this tooth ; this thin incasement of bone may, however, have been an 
inflammatory product. The inner portion of this shell can be seen in 
position. The nerve and its accompanying tissue passes into the infe- 
rior dental foramen immediately against the shell and has the appear- 



590 



EXTRACTION OF TEETH. 



ance of being flattened out. It divides and sends a branch around the 
internal half of the shell. 

Fig. 528. 




Inner side of left half of lower jaw, showing an impacted third molar. 

Figs. 530 and 531 are taken from the right and left halves of the 
lower jaw. Fig. 530 shows the internal surface of the right half; 



Fig. 529. 




(Same as Fig. 528.) 



Fig. 531, the external surface of the same. In Fig. 530 the roots 
of the third molar curve backward, are joined together, and are so 



SURGICAL ANATOMY. 



591 



enlarged by an abnormal deposit of cementum caused by continued 
hyperemia due to the prolonged irritation that the form of each root 
is lost ; the bone also is much thickened. Fig. 531 shows an impacted 



Fig. 530. 




Right half of lower jaw. 

tooth pressing directly against the one in front of it, the roots of which 
have become much enlarged by the deposit of cementum. The sur- 
rounding bone is also thickened and much more compact than the nor- 
mal bone. The character of the cancellated tissue of the lower jaw is 
lost by the deposit of bone caused by continued irritation of that tissue. 

Fig. 531. 




Left half of lower jaw. 

Figs. 532 and 533 show the normal forms of the teeth, and Fig. 534 
is taken from a group of abnormal teeth. If only normal conditions 
of the teeth had to be considered, as shown in Figs. 532 and 533, ex- 



592 



EXTRACTION OF TEETH. 



traction would be a very simple operation, but unfortunately this is 
seldom the case. It often happens that even when the teeth them- 
selves are normal they are situated in abnormal positions, and for this 

Fig. 532. 




Deciduous teeth— left side (Burchard). 



reason alone their extraction becomes necessary. In fact, so varied and 
complicated are the different abnormalities presented that it would be 
impossible to describe them all. The diagnosis of unerupted teeth occu- 



Fig. 533. 




Permanent teeth— right side (Burchard). 

pying abnormal positions has been greatly facilitated by special applica- 
tions of the skiagraphic method. Its general use in this connection is 
but a question of time and further development. A careful study of 
the complications most frequently occurring will, however, give good 
preparation for meeting the emergencies. 

Figs. 525 to 531 and 535 show abnormal positions of various teeth. 
It will be readily seen that no set of rules could be made to govern the 



GENERAL PRINCIPLES. 
Fig. 534. 



.>• * 



593 



& y 






\*/ 





p q r 

Abnormalities in teeth. 

extraction of these teeth ; therefore only the general principles govern- 
ing extraction can be here set forth. 

General Principles in Extracting Teeth. 

These principles may be classified under the following heads : 

(1) Management and Position of Patients. 

(2) Selection of Instruments. 

(3) Technique of the Operation. 

38 



594 EXTRACTION OF TEETH. 

Management of Patients. — The first important step toward a suc- 
cessful operation in dentistry is to gain the confidence of the patient, 
who must be brought to rely entirely on the judgment and skill of the 

Fig. 535. 




Abnormal jaw showing impacted canines. 

operator. If the operator feels entire confidence in his own ability to 
successfully carry out an operation he can, by his manner of approaching 
the patient, impart a feeling of almost absolute trust in his skill. This 
feeling of confidence in himself should be cultivated, as it is evident 
that a slight nervousness on his part, even though he be most skillful, 
Avill tend to alarm the patient to such an extent as may cause great 
interference with the operation. 

Position of the Patient. — The principal object to secure in 
placing the patient is to obtain a good view of the affected tooth and 
contiguous parts ; after which the position should be made as comfort- 
able as possible both for the patient and operator, taking care that the 
territory of operation can be reached with but little strain or effort. 

The position both of patient and operator varies slightly for the 
extraction of each tooth. The main points to be observed are to have 
the particular tooth to be operated upon in view, and the head of the pa- 
tient in such a position that it can be controlled by the left arm and hand. 

The chair should be steady, strong, and comfortable, with arms and 
a good head-rest of rather a concave shape. It should also have a suit- 
able foot-rest. When the regular dental chair is not obtainable, an 
ordinary strong wooden chair can be used. If two of these chairs are 
placed back to back the extra one gives a good place for the left foot 
of the operator, and a head-rest may* thus be made of his thigh. The 
patient should be directed to grasp the seat at both sides with his 



GENERAL PRINCIPLES. 



595 



hands. At times it may be necessary to extract while the patient is in 
bed or on an operating table ; in such cases the operator must obtain 
the best position available. Where an operating table or couch is used 
it is well, if possible, to stand at the head of the couch or table and a. 
little to one side of the patient. By reaching over the head, the for- 
ceps shown in Fig. 488 may be used to advantage in work on the lower 
jaw ; the same forceps may be used for the upper jaw by standing to 
one side of the patient. If the operator is ambidextrous, so much the 
better, as it is very advantageous to be able to use the instrument in the 
left hand, especially in extracting the teeth of the right side of the lower 
jaw. If, however, only the right hand can be used, the operator should, 
as a rule, stand at the right of the chair, the left arm and hand being 
used in various ways to control the head of the patient. The mouth is 
opened as far as necessary, and the left hand is then used to hold the 
lips away and keep the jaw as steady as possible. (See Figs. 543, 544.) 
Selection and Use of Instruments. — The selection of instruments 
depends on the nature of the operation to be performed. The means 
used in extraction should be of the most simple character. Many de- 
ciduous teeth and permanent teeth from about which most of the pro- 
cess has been resorbed can often be easily extracted with the thumb 
and finger. Children feel less apprehension with this method than 
when an instrument is used. The thumb should be covered with a 
napkin and placed on the inner surface of the tooth with the fingers 
against the outside of the jaw. The tooth is then forced outwardly 
toward the cheek or lips. The roots of the deciduous teeth often break, 
but this is of little importance, for when extraction is demanded the roots 
are weakened by the natural process of resorption and will soon disappear. 
Elevators of the various patterns shown in Figs. 500, 501, 536, 537, and 



Fig. 536. 




Manner of holding elevator Fig. 500. 

538 should be used whenever practicable for removing roots, and in some 
cases teeth also. Fig. 500 is especially useful in removing the third 



596 



EXTRACTION OF TEETH. 



molars. When the internal anatomy of the jaws is well understood, 
this will be appreciated. 



Fig. 537. 




Elevator in use labially. 



Fig. 519 shows how firmly the roots are embraced at their necks 
between the two hard plates of compact tissue. It is usually impossible 



Fig. 538. 




Elevator in use lingually. 



to force an instrument between the roots of teeth and these plates with- 
out breaking the internal or external walls of the latter. The cancel- 
lated tissue between these plates is, however, soft and yielding, and into 



GENERAL PRINCIPLES. 597 

this a properly shaped elevator can be passed between the roots. After 
pushing the instrument with the point toward the root to be extracted 
and the back toward the contiguous tooth or root, using the latter as a 
fulcrum, revolve the elevator slightly, prying at the same time, and the 
root will leave its socket with little or no injury to the surrounding tis- 
sue. Elevators should be firmly grasped and held in such a manner 
that if a breakage or slip should occur the instrument will be prevented 
from wounding the soft tissue. If root forceps were used in cases of 
this kind it would be almost impossible to avoid injuring one or the 
other of the plates when removing the root. It is often advisable to 
use the forceps by passing the beaks between the plates and grasping 
the root on its approximal surfaces, instead of the external and internal 
surfaces. Even whole teeth may be extracted in this way when there 
are no adjoining teeth or roots. A similar plan is sometimes used in 
rapid extracting under nitrous oxid, where roots or teeth have been 
extracted on each side of a tooth, the beaks passing into the sockets 
of the extracted teeth, thus grasping the tooth to be removed on its 
approximal sides. This mode of operating must be followed with 
care, especially in teeth situated below the maxillary sinus, as the floor 
of that cavity may be easily injured. (See Figs. 516 and 517.) 

Lancing. — Lancing for extraction is not usually required, though 
there are cases where it is quite necessary. If the teeth have been 
standing alone for a long time, especially those in the back part of the 
mouth, the gums are apt to become firmly attached to them ; when this 
is the case it is well to sever the connecting tissue by the use of the 
lancet before extracting. In extracting roots where it is necessary to 
remove a portion of the external plate of the alveolar process, it is well 
to make an incision in a line over the root, through the gum to the 
bone ; it is even advisable to slightly dissect the gum and periosteum 
from the bone on each side of the cut. This is done in order that the 
external beak of the forceps may be passed along the bone as far as de- 
sired. By thus lancing, the parts will afterward come together and 
quickly heal, whereas if the gum is cut by the forceps it will not heal 
so well. In extracting roots in the lower jaw, if the lancing w r ould 
cause the blood to cover the parts and obscure the operator's view it 
should be omitted. 

Use of Forceps. — As nearly all operators are right-handed, the 
instruction as to the use of forceps will be given with that understand- 
ing, most of the special instruments being made for that hand. The 
forceps are grasped in the right hand with the palm toward the body, 
the thumb on top of and partially between the handles (w r hich will indi- 
cate to a great extent the amount of pressure being exerted upon the 
tooth), pressing against the handle nearest the palm just back of the 



598 



EXTRACTION OF TEETH. 



joint. The first finger should rest a little between the handles, thus 
giving a firmer grip on the right handle (see Fig. 539), which might be 



Fig. 539. 




Use of forceps. 



termed the fixed, or passive, handle ; while the other one is the movable, 
or active, handle. Many operators do not place the first finger between 



Fjg. 540. 




Use of forceps. 



the handles (see Fig. 540). The second and third fingers pass to the 
outside of the left handle and are used to close the forceps, while the 



GENERAL PRINCIPLES. 599 

little finger resting between the handles is used to open the forceps, 
the thumb being used to force the beaks into the required position. 
After the forceps are in position for extracting, the first finger is 
placed along the side of the second finger to give more power to 
extract. 

After it has been decided to extract by using the forceps, the par- 
ticular forms indicated must be selected and arranged in a convenient 
place, ready for immediate use as needed. Especially should this be 
the case when the operation is done under the anesthetic influence of 
nitrous oxid. It is under such conditions that the fewer forceps used 
the better ; the writer generally uses but one forceps (Fig. 489) for the 
extraction of any or all teeth except the first and second molars ; for 
those teeth, when the other teeth are in position, he advises using the 
special forceps. 

Having the patient's head in position, the forceps are grasped as 
previously described and the beaks adjusted to the tooth. As a rule, 
the inner beak should be placed in position first, and then the outer 
one — this is very important, especially for the lower teeth — taking care 
not to include a portion of the tongue or the soft tissues of the floor 
of the mouth, as both are liable to get in the way. When the forceps 
are adjusted to the inner and outer surfaces of the tooth, they should 
be forced between it and the gum until they come in contact with the 
edge of the alveolar process. It is a common error of students to use 
too much force in pressing the handles together; only sufficient force 
should be used to securely hold the tooth or root. The forceps should 
grasp as much of the roots as possible, avoiding pressure upon the 
crown and being careful not to force the beaks between the alveolar 
plates, as this would result in breaking one or both plates over the 
tooth or root extracted and also over the adjoining tooth. Cases have 
occurred in which the entire external plate of one side has been forced 
off in this way. 

At times it may be advisable to take away a portion of the outer 
plate, in which case the lancet shown in Fig. 502 should be used to cut 
through the gum a little beyond the point of process to be removed, 
dissecting up the gum slightly ; the inner beak is then adjusted and the 
outer one passed between the divided gum and the process as far as 
required ; the forceps should then be closed with only sufficient force 
to cut through the bone and grasp the tooth, taking care not to 
crush it. 

After the forceps are in position the tooth is loosened by rotating it 
slightly if it be a round conical-rooted tooth, such as a central incisor, 
but if it be a flattened one it should be removed by an outward and 
inward movement. 



600 EXTRACTION OF TEETH. 

By the u out-and-in motion " is meant that after the forceps are ap- 
plied the force used in loosening teeth is directed in such a manner 
that the tooth is worked outward and inward from the median line 
of the mouth (see Fig. 51 9, in which the lines show the direction of 
the motion for each tooth). The individual teeth do not always bear 
the same relation to the median line of the jaw as shown in Fig. 519. 
When the axis of a tooth is not regular it should be loosened by mov- 
ing backward and forward, and the movement should be in line 
with its strongest diameter, which lessens the danger of breaking the 
tooth. 

In the upper jaw the inward movement is made after the outer, but 
with not so much force, as the structure on the inner side is more 
dense. 

Eotation of a tooth in extracting is seldom practiced, as the single- 
rooted teeth are usually flattened and teeth that have more than one 
root cannot be rotated. Of the single-rooted teeth, the upper central 
incisors alone have roots nearly conical in shape which permit rota- 
tion as well as the out-and-in motion. A rotary motion is usually of 
advantage in extracting the roots of the upper first bicuspid when 
double, and of the upper molars after the crowns are broken away so 
that the roots are disunited. These roots are usually round, conical, 
and somewhat curved in shape. 

If possible, the tooth should be kept in view during the operation 
so that the results of the movements may be seen. A beginner may 
let the forceps slip and extract the wrong tooth when he is not observ- 
ing each movement, but an experienced operator can depend on his sense 
of touch to a very great extent. The amount of pressure a tooth will 
stand while loosening it by an •" out-and-in motion " depends on the size, 
condition, and density of the bony tissue surrounding it. Experience is 
the only reliable guide in this matter. When a tooth resists ordinary 
effort, if the operator is not quite sure of the cause of the resistance 
of the tooth, it is better to desist temporarily and allow the patient to 
rest in order to investigate the condition of the tooth and its surround- 
ings. Fig. 530 will give some idea of the causes of the resistance 
offered by apparently normal crowns. 

After the forceps are applied and the tooth slightly moved, if the 
operator has a cultivated sense of touch he will feel that the tooth is 
yielding in one particular direction ; as a general rule the tooth should 
be carried in that way. 

The force applied to safely and judiciously extract teeth should be 
made with arm and wrist motion ; if the whole body is used the sense 
of touch is blunted and accidents are liable to occur. 

Extracting- Deciduous Teeth. — In extracting the deciduous teeth 



GENERAL PRINCIPLES— DECIDUOUS TEETH. 



601 



the principles involved are nearly the same as for the permanent. A 
care, however, must be taken that is not necessary with the perma- 
nent teeth, i. e. to avoid injuring the developing permanent teeth that 
are situated immediately beneath them. 

Fig. 541, which shows all the deciduous and the developing perma- 
nent teeth except the third molars, gives a true idea of their relative 
positions. Special attention is drawn to the position of the crowns of 
the bicuspids as related to the deciduous molars. It will be seen that 
they are situated between the roots of the latter teeth, and by using 
undue force in adjusting the forceps these crowns could easily be mis- 
placed, extracted, or injured. 

If the deciduous teeth are extracted at the proper time they can 
usually be removed by the thumb and finger as described. If not, 
one of the forceps shown in Figs. 488 and 489 should be used. 

Fig. 541. 




Dentures of a child six years of age. 



Extraction of Individual Permanent Teeth. 

The anatomy of the individual teeth and the majority of their 
often-repeated variations as well as the general principles govern- 



602 EXTRACTION OF TEETH. 

ing the extracting operation being understood, the extraction of each 
tooth will now be studied, those of the upper jaw being first 
considered. 



The Upper Teeth. 

THE CENTRAL INCISOR. 

This tooth has a strong, round conical root. The forceps are carried 
into position by placing the inner beak at the palatal surface of the neck 
of the tooth ; the outer one is then placed in position and the instru- 
ment forced upward with a slight rotary motion between the gum and 
the tooth until it comes in contact with the alveolar process. As the 
root is round and conical, it is loosened by rotation and the out-and- 
in motion and then removed by drawing it directly from its socket. 
It is, as a rule, easily extracted. 



THE LATERAL INCISOR. 

This tooth is much smaller than the central. The root is flattened 
and somewhat curved, the apex being often bent in the direction 
of the canine teeth. After applying the forceps as directed for 
the central incisor, the motion should be outward and inward. As 
the tooth has a delicate root, the force used must be light. When 
loosening and removing it, care must be exercised, as its root is not 
straight. The tooth is carried in the direction of the least resistance, 
which is usually toward the canine tooth. 



THE CANINE. 

This tooth is usually more firmly set in the jaw than any other, and 
it often requires considerable force to break up its attachments. The 
root is long and slightly flattened. After applying the forceps its 
attachments are broken up by the out-and-in motion. After loosening 
it is usually easily removed from its socket. As this tooth is erupted 
after the adjoining teeth are in position, it is often malposed. If the 
deciduous canine has been lost before its proper time, and the first 
bicuspid has pushed forward, there is no room for the canine to take 
its true position. This irregularity varies to a great extent. The 
canine may also be out of position from unknown causes. A marked 
specimen is seen in Fig. 535, where both canines are impacted. They 
were entirely covered by a bony lamina. 

Sometimes the roots of these teeth project into the maxillary sinus, 



THE VPPER TEETH. 603 

or even into the nasal chamber, while the crowns are impacted be- 
tween the palatal plate and the plate forming 
the floor of the nose. Fig. 542 represents a Fig. 542. 

canine, lateral, and central incisor which were . ^ p 
extracted from the sinus, the roots being Oi f'\ j \ 
imbedded in its inner wall. Teeth thus im- / '-= \ wA r*$ 

pacted are often a source of trouble in vari- '■„ \ / / \ 

f ■ ■ ■' &l - 

ous ways and when discovered should be re- CL > '*. ^^ 

moved. When the tooth is SO covered by bone Canine, lateral, and central 

that the forceps cannot be applied the" bone S2S™? from 
must be cut away sufficiently to allow the forceps 

to grasp it. A very good instrument for removing the bone in the 
upper jaw is the elevator shown in Fig. 500 ; after the point has been 
sharpened it may be used as a chisel or gouge. 

THE BICUSPIDS. 

The first bicuspid usually tas a bifurcated root and the only motion 
that can be used safely for loosening is the out-and-in, as these roots are 
sometimes considerably divergent. The removal after loosening is not 
always easily accomplished, a little outward pressure being frequently 
necessary. If the force required is used too suddenly the inner root is 
liable to break. 

The second bicuspid usually has a single flattened root, though occa- 
sionally it is bifurcated. The motion used to loosen this tooth is the 
outward and inward, using the same precaution as with the first bicus- 
pid on account of the possibility of a double root. 

THE FIRST AND SECOND MOLARS. 

These teeth are nearly similar, having three roots, two buccal and 
one palatal, which vary so much in degrees of separation that no set 
rule can be given for their extraction. The roots of the first are usually 
more divergent than those of the second. Only the out-and-in motion 
can be used, rotation being out of the question in loosening them, as 
the roots often diverge to a great extent. (See p, Fig. 534.) After the 
tooth has been loosened there is at times a difficulty in removing it, 
on account of the distance around the three roots ; owing to their 
divergence this distance is greater than the size of the anatomical 
neck of the tooth corresponding to the opening of the socket. The 
only general rule that can be given is to carry it in the direction of 
the least resistance. Each tooth has more or less of an individual 
character, and therefore the operator must be governed by circum- 
stances. The main precaution to be observed is not to be in too 
great haste, as there is danger of breaking one of the roots or re- 



604 



EXTRACTION OF TEETH. 



moving a large piece of the outer plate of the alveolar process. (See 
Accidents, p. 612.) 

THE THIRD MOLAR. 

This tooth so varies as to the shape and number of its roots that it 
is seldom spoken of as an abnormal tooth, no matter in what form or 

Fig. 543. 




Showing position for extracting upper teeth of left side. 

position it may be found ; the greater number have roots curved back- 
ward and outward. Their position in the jaw also varies considerably, 
The forceps shown in Fig. 488 is the instrument to use in extracting. 
After the forceps have been firmly placed, the principal motion is the 
out-and-in, though more out than in. If there is much resistance the 
hand should be carried outward and upward, or in the direction of the 
least resistance. This tooth is sometimes erupted at the side of the 



THE UPPEE TEETH. 605 

alveolar process (Fig. 545) with its occlusal surface pointing toward 

Fig. 544. 




Showing position for extracting upper teeth of right side. 

the cheek. It is not well to have the mouth opened too far, as it 
brings the coronoid process of the lower jaw in the way. 

Fig. 545. 




An impacted third molar. 

In stating the general rules of extracting, caution was given not to 



606 EXTRACTION OF TEETH. 

make the movements faster than could be seen ; this applies very partic- 
ularly to the third molar. It is so near the ascending ramus in the 
lower jaw that it is possible, especially when the roots are curved and 
spread out, to fracture this angle, or in the upper jaw the tuberosity may 
be broken away, thus opening into the maxillary sinus. The gum tis- 
sue often adheres to the posterior portion of this tooth ; when this hap- 
pens it is best to desist from attempts at extraction and sever the tissue 
from it with a curved lancet or scissors before removing the tooth with 
the forceps, or, as before advised, dissect the gum away before applying 
the forceps. 

The Lower Teeth. 
As a rule, the teeth of the lower jaw are more difficult to extract 
than are those of the upper jaw, the lips and cheeks being in the way. 
The tongue is also troublesome, covering the tooth, and when the inner 
beak of the forceps is placed in position especial care must be used to 
prevent part of the tongue or floor of the mouth from being caught in 
the instrument. 

THE ORAL OR ANTERIOR TEETH. 

(For position see Fig. 546.) 

These six teeth have small single, straight, compressed roots. Their 
extraction is only necessary when they become loosened by accident or 
from disease or when it is necessary to clear the mouth for inserting 
artificial teeth. The operator should stand a little back and to the 
right side of the chair, being somewhat elevated above the usual posi- 
tion. Pass the first finger of the left hand between the lips and the 
alveolar border, and place the remaining fingers beneath the chin with 
the thumb on the inside of the teeth. For the incisors use the lower 
root forceps shown in Fig. 499 or the universal forceps shown in Fig. 
489. The canines are larger and more firmly set : delicate root forceps, 
therefore, are not usually suitable ; the instrument shown in Fig. 489 
or, better, the bicuspid forceps (Fig. 497) are much to be preferred. 

An out-and-in motion is proper for loosening all these teeth. 

THE BICUSPIDS. 

The lower bicuspids have compressed roots seldom bifurcated, and 
are generally extracted by the out-and-in motion. The special forceps 
for these teeth should be made so that they grasp a considerable por- 
tion of the surface of the tooth. These teeth are often difficult to 
extract without breaking when all the teeth are in position, the roots 
being long and narrow and often situated in an awkward position. As 
shown in Fig. 518, the position of the roots of the second bicuspid is 
a little to the inner side of the anterior root of the first molar. The 



THE LOWER TEETH. 607 

tooth illustrated in this particular case would be very difficult to ex- 
tract without breaking. 

Fig. 546. 




Showing position for extracting lower anterior teeth. 
THE FIRST MOLAR. 

(For position see Fig. 547 for the left side, Fig. 548 for the right 
side.) 

The first molar, if in a mouth where all the teeth are in position, is 
generally the most difficult of all the teeth to extract. The roots are 
usually long and diverging. It is lower in the arch than the other 
teeth, and is in fact similar to an inverted keystone ; consequently, 
when extracted it is drawn through the arch. When the teeth are close 
together the second bicuspid and second molar yield a little, but great 
care must be taken that one or both of these teeth are not extracted 



608 



EXTRACTION OF TEETH. 



with the first molar. In placing the forceps on the lower molars the 
points of the beaks of the special molar forceps (Fig. 485 or 498) are 
placed in between the roots on each side of the tooth. Care should 
be exercised to avoid including a portion of the tongue or soft tissues 
of the floor of the mouth in the forceps. If the forceps are not well 
placed the wrong tooth may be extracted , as it is possible for them to 
slip in between two teeth. 

In loosening these teeth the out-and-in motion is used, and as they are 
wedged in it is often necessary to continue this motion while extracting 
them from their sockets. At times it is advisable to move the tooth out- 

Fig. 547. 




Showing position for extracting lower teeth of the left side. 

wardly after it has been slightly lifted from its socket. Occasionally the 
roots diverge so far that either the crown has to be broken from the 
roots at their bifurcation or the tooth divided in the line of bifurcation 
with splitting forceps ; each root being then extracted separately. 



THE SECOND MOLAR. 

The roots of this tooth are not as diverging as those of the first 
molar, as may be seen by examining Fig. 514, nor is the tooth wedged 
in as tightly as in the case of the first molar. 

The out-and-in motion is required for these teeth, using the same 
precautions that are necessary in the extraction of the first molar. 



THE LOWER TEETH. 



609 



THE THIRD MOLAR. 

In these teeth the roots may vary so much in number and shape 
that there can hardly be said to be a typical third molar. Fig. 514 
shows what might be called a normal third molar, but these are only 
found in well-developed jaws, where the teeth are not so large as to 
cause crowding. They vary in character from the one shown in Fig. 

Fig. 548. 




Showing position for extracting lower teeth of the right side. 

514 to the two shown in the right and left jaws represented in Figs. 
530 and 531. Figs. 526, 527, 528 and 529 show other forms and posi- 
tions of the third molar. There are also third molars having three, 
four, or five roots, a, Fig. 534, shows another form of the third molar; 
b, c, d, e, and / show where the third molar has united with the second 
molar; g and h illustrate three molars united; jf, h f I, m, n, o, andp show 
variations of roots. The positions these teeth occupy may vary in all 
degrees from that shown in Fig. 514 to those shown in Figs. 525-531. 
Where the third molar is in the position shown in Fig. 514 and there 
are no other complications, its extraction is easy. The tooth is removed 
by placing either the special lower molar forceps shown in Fig. 498 or 
the forceps shown in Figs. 488 and 489 in position, and using the out- 
and-in motion with a slight raising of handles. If 488 be used the 

39 



610 EXTRACTION OF TEETH. 

beaks should be turned downward and the handles carried upward. 
But when it is of irregular form and position, as shown in the various 
illustrations, the difficulty increases with the degree of variance from 
that of the normal tooth shown in Fig. 514. These cases should be 
closely studied. If portions of the teeth are in view, as shown in Figs. 
530 and 531, they will assist to some extent in the diagnosis of the 
position of the roots. In this particular case, the bone as well as the 
roots being much hypertrophied, it would be impossible to extract the 
roots without fracturing the process to a greater or less extent. It will 
be noticed, on examining the section Fig. 530, that to have fractured 
the inner portion of the jaw the inferior dental nerve and vessels and 
also the mylo-hyoid nerve and vessels would be endangered. If in 
attempting to extract this tooth it should not yield to a pressure which 
if increased would break the bone, it is better to desist and cut away 
the bone with a bur (shown in Fig. 587) in the surgical engine, as 
was done in the case of the specimen from which the illustration was 
made. Those represented in Figs. 526, 527, 528, and 529 would be 
more difficult to diagnosticate, as no portion of the teeth is in view. 
If trouble existed in this region, the explorations would have to be 
made with sharp steel probes. The bone would then have to be cut 
away until the tooth could be grasped by the forceps, the forceps shown 
in Fig. 488 being the most useful for this purpose. 

In Fig. 525 the third molar is in such position as to be easily ex- 
tracted, though if proper care were not used the extraction might have 
serious consequences. It will be noticed that the points of the roots are 
just through the inner U-shaped cortical portion of the lower jaw below 
the mylo-hyoid ridge and project into the submaxillary region. Now, 
should this tooth or the roots be pushed downward in attempted ex- 
tracting, as is sometimes taught, it might be forced into the submaxillary 
region and consequently be lost for a time, with the possibility of having 
to perform a subsequent surgical operation to cut it out from the neck. 

An impacted third molar often causes great distress by initiating an 
inflammation which extends to the region surrounding the angle of the 
jaw, and often including the temporo-maxillary articulation and soft 
parts within the mouth. Under these conditions the jaws can only be 
partly opened, deglutition is impaired, and solid food cannot be taken. 
One of two things must be done : either the offending tooth or the 
one in front of it must be extracted. Every effort should be used to 
extract the third molar ; if any part of the tooth can be seen, the diffi- 
culty is not so great ; the inflammation of the adjacent parts will gen- 
erally quickly subside. As the mouth can only be opened slightly, 
it is impossible to use the large special molar forceps. An elevator 
is sometimes recommended in these cases, but it may prove to be a 



TREATMENT AFTER EXTRACTION. 611 

dangerous instrument to use under such conditions, for when the tooth 
is lifted out of its position in the mouth, it might easily slip back into 
the larynx. It is well in some cases to loosen a tooth with an ele- 
vator and then remove it with the forceps shown in Figs. 488 or 489, 

Fig. 549. 




Showing the direction in which the lower third molar is to be extracted. 

as they are small and are so shaped that the beaks can be carried back 
to the tooth mainly along the vestibule of the mouth, the inner blade 
being placed between the teeth by passing the forceps back of the second 
molar. Often it is impossible to see completely what is being done, 
therefore it is not well for a beginner to undertake this kind of extract- 
ing. After the forceps is in position the tooth should be worked in 
any direction in which it will yield ; this is generally outward, upward, 
and backward, in the manner of unfastening a hook. (See Fig. 549.) 
When the third lower molar is impacted near the angle of the jaw, it 
may be necessary to open it from the outside through the soft tissues. 
When such is the case the surgical engine should be used for cutting 
the bone. 

Treatment after Extraction. 

The operator should recognize immediately any accident that may 
have happened during the operation of extraction, and treat it as the 
circumstances indicate ; but if nothing unusual occurs, then the patient 
may be allowed a few moments' rest, after which the mouth should be 
carefully examined. If there are any loose portions of the process or 
pieces of gum hanging to the parts operated upon, they should be re- 
moved by any convenient means, such as a curved pair of scissors or 
a curved lancet (Figs. 502 and 504). 

When several teeth have been extracted leaving ragged edges of the 
outer walls of the alveolar process, these should be removed with the 



612 EXTRACTION OF TEETH. 

excising forceps, or better still, by the use of either forceps Fig. 488 or 
489, according to circumstances, as the beaks can be carried between the 
gum and the process better than can the blades of the excising forceps. 

An antiseptic mouth- wash consisting of a tablespoonful of phenol 
sodique to a glass of water should be used several times daily for the 
next few days. Any other suitable antiseptic mouth -wash which may 
be more agreeable to the patient may be used instead, though the phenol 
sodique is highly efficacious. 

Occasionally, in a few days after extraction, pain will be noticed in 
and about the alveolus, especially when the tooth has been the seat of 
pericemental inflammation. Relief in such a case is usually given by 
removing any clot that may have formed, and breaking down the de- 
generated tissues which should have adhered to the root. A pledget of 
cotton saturated with the full-strength solution of phenol sodique or 
campho-phenique should then be inserted as a dressing. 

Accidents. 

When accidents of any kind whatever occur, the operator should be 
calm and appear perfect master of the situation. He should be pre- 
pared to successfully deal with whatever conditions may arise. 

One of the most common accidents is the breaking of a whole or 
portion of a tooth or root. If the operator has any doubt of his ability 
to remove the tooth entire, he should inform the patient that there is a 
possibility of its breaking, in which case not to be alarmed. If the 
tooth is removed without breakage so much the better ; even if it does 
break it will not cause alarm to the patient. It is more desirable that 
all of a tooth should be removed, for if its surrounding membrane has 
been inflamed, or if a root has been broken having a portion of the 
pulp attached, either will be the source of obstinate pain. 

It is better, however, under some circumstances, to let certain roots 
remain if they are broken, than to break away a large amount of process. 
Roots are sometimes so situated that they can be easily forced into the 
maxillary sinus (see Figs. 516 and 517), or into the submaxillary region 
(see Fig. 525), or upon the inferior dental nerve. If there are good 
reasons for believing that the root will not cause undue pain, and there 
is danger of breaking a large amount of process, it is preferable to let 
it remain, as in a short time the contraction of the soft parts and the 
expulsive efforts of Nature will force the root outward and it can then 
be removed without danger. If roots are forced into the maxillary 
sinus they must be followed and removed. 

When several teeth are to be extracted under an anesthetic, if the 
gum should adhere unduly to one of them, the operator should desist 
from its removal and proceed with the other extractions, after which 



ACCIDENTS. 



613 



the adherent gum should be severed with a curved lancet or a pair of 
curved scissors and the tooth then removed. If the gum be much 
torn and the bone exposed to a great extent, it should be held in place 
by a few interrupted sutures. If, however, proper care is taken in ex- 
tracting, this should not occur. 

In extracting crowded teeth, or those having frail alveolar surround- 
ings, it is possible to remove a piece of the alveolar plate, especially in 



Fig. 550. 




Fig. 551. 




Fig. 552. 




Fig. 553. 



Fig. 554. 



Fig. 555. 






Fig. 556. 



Fig. 557. 



Fig. 558. 






extracting the first and second molars, the broken piece extending back- 
ward, forward, or in both directions to the adjoining tooth. (See Figs. 
550 to 558.) The tooth in front may even be partially lifted from 
its socket. As soon as the operator sees the impending accident he 
should either stop and see if his method of extraction could be im- 
proved, or, this point being negatively decided, hold the parts in posi- 
tion with the left hand as well as he can, and after the tooth is removed 
force the injured parts into position ; they will usually stay, but if not^ 
appliances of appropriate form can be used for retention. 

In extracting the upper third molar, the tuberosity is sometimes 
broken away, opening into the maxillary sinus (see Figs. 550, 551, 552, 



614 EXTRACTION OF TEETH. 

555, and 558, showing where teeth have been carried away with the 
tuberosity). If it is a simple fracture the parts can be forced into place 
and they will in a short time reunite. But if the parts are torn loose it 
will be of little use to try to replace them ; the best course is to trim 
away the ragged edges, using the curved scissors for this purpose. 

After such a fracture it is possible that hemorrhage may occur from 
rupture of the superior dental artery. This is sometimes difficult to 
control. One of the best remedies, however, is to tightly pack the parts 
with medicated gauze. This application must be left in for a few days 
and then be carefully removed. It is sometimes well to take out only 
part of the gauze at a time, the loosened portions being cut off with a 
pair of curved scissors. Hemorrhage after extraction usually ceases in 
a short time, and then there is no occasion for treatment ; when, how- 
ever, the adjoining parts are much inflamed, or the patient is in an 
anemic condition, or the case is one of hemorrhagic diathesis, special 
treatment will be necessary. 

Hemorrhage of extraction may be divided into tw T o classes, arterial 
and capillary. When arterial, it is usually located in the socket of 
the tooth, and may usually be stopped without much difficulty by taking 
a twist of absorbent cotton, shaping it into a thin tapering roll, and 
thoroughly packing the socket. Before inserting the cotton tampon, 
it should be rolled in tannic acid until the fibers will hold no more, 
then the cotton is to be packed tightly into the alveolus with a dental 
plugger. In packing the cotton it is well to begin at one end and 
crimp it upon itself until the socket is entirely filled. A narrow strip 
of iodoform gauze when packed in the same way makes a good plug, 
and the more rapid healing of the parts afterward and freedom from 
any offensive odor makes it a more satisfactory tampon than the tannic 
acid and cotton plug, though the styptic quality of the latter makes it a 
more efficient hemostat. The plug in a few cases may require retention 
in position by compression. This is accomplished by holding a few 
folds of muslin or similar material over the plug, closing the mouth 
and binding the jaws together with a few turns of a Barton's bandage. 
(See Figs. 559 and 560.) The 25 per cent, ethereal solution of hydrogen 
dioxid in small quantity on cotton packed into a bleeding socket is a 
most efficient styptic, and will effectually control severe hemorrhage 
after extraction. Care must be exercised not to use the solution in 
excess, as it may cause injury to adjacent parts. 

Where hemorrhage occurs from the surrounding tissue, as in patients 
in an anemic condition or in cases of hemorrhagic diathesis, the case 
usually falls into the hands of a general practitioner for systemic 
treatment, but the local treatment usually employed by physicians in 
these cases is often unsatisfactory, many using MonsePs solution of 



ACCIDENTS. 615 

persulfate of iron, which, although it may be a good styptic for use in 
Fig. 559. Fig. 560. 






Barton's head bandage. 

other parts of the body, should not be used in the mouth. The local 
treatment in such cases, whether soon after extracting or not, is first 
to remove all clots from the wound and find the exact place or places 
from which the blood is exuding. A suitable styptic and compression 
are the principal means used for stopping it, the latter perhaps being 
the most important. Tannic acid applied on cotton, lint, or similar 
substances, is a good styptic to use in the 
mouth. Iodoform gauze, for the reasons al- ^ * 56 ^1 

ready given, is better, although it has not 
been generally used in this connection. Com- 
pression can be applied as the ingenuity of 
the operator may direct. When a hemor- 
rhage occurs from a socket between good 

° nil Showing compress and ligatures. 

teeth, it can be readily controlled by two 

ligatures, making one fast to each tooth, then placing in position and 
tying the four ends together over the compress, as shown in Fig. 561. 
In a few rare cases an impression of the parts should be taken in wax 
or other modelling compound in order that a rubber or metallic plate 
can be made to hold the styptic compress in position. After the com- 
press is in position warmed modelling compound can be placed over it 
and the jaws brought together and retained in place by a head bandage. 
A plug of hardening plaster of Paris may be made and forced into 
the bleeding socket in obstinate cases, or in extremis the extracted tooth 
might be soaked well in phenol sodique and reinserted. 

The systemic treatment is often important; if the patient is seen 
to be anemic or known to be of the hemorrhagic diathesis, the treat- 



616 EXTRACTION OF TEETH. 

ment should be begun before extracting. This is done by thoroughly 
building up the system by a course of hygienic and tonic treatment. 
The cause of bleeding in cases where the hemorrhagic diathesis exists 
is but imperfectly understood ; the blood may be so defibrinated that it 
has lost the power of coagulation and so will not form a clot, or the 
muscular coats of the vessels have lost their tonicity, either through 
general debility or the lack of energy in the vasomotor nervous system, 
which prevents their contracting so as to close the lumen. Certainly 
the walls of the capillaries permit free transudation of the blood. 
In good health the proper coagulation and the contraction of the blood- 
vessels will stop the hemorrhage even when an artery of consider- 
able size is lacerated, especially if the flow be held in abeyance by arti- 
ficial means for a short time. It is when the blood will not coagulate 
and the vessels fail to contract that a thorough systemic treatment must 
be given. This lack of normal function on the part of the blood and 
vessels may arise from various diseases, and in order to judiciously 
treat a patient exhibiting the hemorrhagic diathesis a thorough exam- 
ination must be made and such treatment given as the diagnosis indi- 
cates. Among the most common causes of hemorrhage are anemia, 
syphilis, purpura, tuberculosis, and a generally impaired vitality, rarely 
an over-acting heart ; the passive hyperemia attendant upon a weak 
heart is a potent factor requiring a course of preliminary treatment. 

Specific and special diseases must of course receive the treatment 
peculiar to these conditions. On general principles the following tonics 
are advisable : Quassia, cinchona and its alkaloids, iron in its various 
forms, sulfuric and hydrochloric acids, arsenic, phosphorus, nux vomica 
and its alkaloid strychnin. With these general tonics various hemo- 
statics can be given, such as alum, tannic acid, ergot, erigeron Cana- 
densis, and gallic acid. Very frequently the digestive organs require 
special medication, when such remedies as pepsin, pancreatin, hydro- 
chloric acid, and bismuth subnitrate are indicated. 

The following prescriptions have proved to be very excellent in 
their special province. 

As general tonics : 

]^. Strychnia? sulphatis, 

Acidi arsenosi, ad. gr. j ; 

Quinise sulphatis, gr. xxx ; 

Ferri sulphatis exsiccat., gr. xv. 

M. et ft. piluke No. xxx. 

S. One immediately after each meal. 

1^. Elixir ferri, quinise et strychnia?, f^iv. 

S. Teaspoonful four times daily. 



USE. OF GENERAL ANESTHETICS. 617 

To improve digestion and assimilation : 

1^. Acidi hydrochlorici diluti, f^ij ; 

Ext. ignatise amaris fid., f^j • 

Pepsin, 3iss ; 

Ext. ipecacuanha? fid., TTLiv ; 

Infusi gentianse comp., q.s. ut ft. f 3yj. — M. 
S. Dessertspoonful in sherry glass of water immediately after 
meals. 

In cases of undue hemorrhage after extracting, it is well to adminis- 
ter a hemostatic while at the same time styptics and pressure are being 
applied locally. The following are very good : 

1^. Vin. ergotse (Squibb's), f^iij. 

S. Teaspoonful every two hours. 

1^. Ext. ergots solidificat., 3j ; 

Ext. cannabis indicse, gr. v ; 

Strychnia? sulphatis, gr. ss. 

M. et ft. pilulse No. xxx. 
S. One pill three times a day. 

Gallic acid and aromatic sulfuric acid may be administered. 

Digitalin exhibited in doses of y 1 ^ to \ a grain three or four times daily 
for a series of weeks will often effect such change in the capillaries as to 
overcome the hemorrhagic tendency. This has been repeatedly and suc- 
cessfully accomplished in epistaxis, and as the conditions are analogous 
it can be employed in this diathesis with expectation of similar results. 

Extraction under the Influence of General Anesthetics. 

While it is undoubtedly true that the extraction of teeth under the 
influence of a general anesthetic is in accordance with the general spirit 
of the age which seeks to spare all suffering or cause the infliction of 
but slight pain, yet many evils attend such general and too often 
indiscriminate use. " A patient under the effect of so powerful a 
drug that consciousness is destroyed is nearer death than an ordinary 
human being, since the primary depressive influence upon the high 
nervous centres may speedily pass to the lower vital centres in the 
medulla oblongata." l 

The indiscriminate use of general anesthetics, beside their possible 
danger to life and health, has an accompanying evil in the demand 
for the extraction of teeth which are salvable and useful, but which 

1 H. A. Hare, in Park's Text-Book of Surgery, vol. ii. 



618 EXTRACTION OF TEETH. 

a patient insists upon having removed in order to avoid the discom- 
fort attendant upon their treatment and filling. No one questions 
or denies the enormous benefit of general anesthetics in dentistry, 
particularly when painful operations are to be performed upon ner- 
vous women and children, but if the patient be willing to suffer a little 
pain it is generally better to extract without a general anesthetic, as in 
that case the patient can assist the oj)erator by keeping the head in 
a desired position with the mouth and lips well open, and in various 
other ways, while under the influence of an anesthetic the muscles 
supporting the head, jaws, and cheeks are so relaxed that it is difficult 
to keep the mouth and lips well open. 

If the operation is to extract a difficult tooth, the operator is limited 
to the time when the patient is under the influence of an anesthetic, and 
in the case of nitrous oxid the time is Yery short ; but without an anes- 
thetic there is not this limitation as to time, and the extraction may be 
done with that care and deliberation essential to a proper operation. It 
is an important rule in any branch of surgery that the time required to 
do an operation must be sufficient to do it properly and without un- 
necessary injury to the adjoining tissues. 

Examination of a Patient before the Administration of a Gen- 
eral Anesthetic. — The physical examination should be made in such a 
way that it will not cause alarm to the patient. The result of this ex- 
amination governs the selection of the anesthetic, and to some extent 
shows how far the patient should be carried under its influence. It has 
been said that a greater amount of care should be used if the patient 
has or is suspected of having organic or functional disease of either the 
heart or the lungs. This is quite true, but at the same time the greatest 
amount of care should be observed in all cases. For the physiological 
action of various anesthetics the student is referred to special works on 
this subject. 

The question often arises whether anesthetics should be used at all 
if the patient has either organic or functional disorder of the heart. 
That depends to a large degree on other conditions of the patient. If 
the shock of extraction will be less under ether or nitrous oxid, then by 
all means give the anesthetic and carry the patient fairly well under its 
influence, so that there will be neither pain nor knowledge of the ope- 
ration. Occasionally patients suffering from heart disorders can bear 
a certain amount of pain without shock ; in such cases it is better, if 
the operation be a simple one, to extract while in the normal condition. 

The use of ether for extracting has certain advantages. If for any 
reason the operation requires longer time for its performance than the 
influence of the nitrous oxid will last — say from one to two minutes 
— it is better to use ether. Ether can be given after the patient has 



USE OF GENERAL ANESTHETICS. 



619 



Fig. 562. 




become anesthetized by nitrous oxid and oxygen and he may be kept un- 
der its influence for a considerable time ; in this way the struggling stage 
of ether is avoided. When the teeth are to be extracted at the patient's 
home or at any other place outside of the office, ether is more conve- 
niently carried than nitrous oxid. If properly used and the patient has 
perfect confidence in the operator, it can be so administered that one, 
two, or three teeth may be extracted during what is known as the first 

stage of ether anesthesia, before complete 
unconsciousness and long before the strug- 
gling stage commences. 

The best way to accomplish this is to 
administer the ether in a cone made by a 
napkin or towel, with the small end slightly 
opened so as to allow the patient to inhale 
a small quantity of air ; it also permits the 
patient to exhale freely and with a less suf- 
focating effect. It is well to place in the 
cone a small soft sponge that has been well 
washed with hot water. After the cone is 
ready the patient should be instructed to 
breathe several long and full inhalations ; this 
clears the lungs of much impure air and ac- 
customs the patient to the 
kind of breathing required. 
Then the appliance is placed 
in front of and some distance 
from and above the mouth 
and nose, being careful to 
allow none of the ether to 
drop from the cone upon the 
face, as it will demoralize the 
patient. The inhaler is to be 
advanced toward the face 
slowly and gradually, watch- 
ing the effect upon the pa- 
tient ; if there is a tendency 
to cough, the advance should 
be interrupted until this has 
passed. After the cone has closed tightly over the mouth and nose, 
it is a good plan to ask the patient to hold up the left hand as long 
as possible ; this will concentrate his thoughts upon the act and away 
from the operation. When the hand begins to fall, the request to raise 
the hand should be repeated ; it will soon fall, and in a few seconds 



Nitrous oxid gasometer. 



620 



EXTRACTION OF TEETH. 



afterward one, two, or three teeth may be removed, the number de- 
pending entirely upon their position and the difficulty to be overcome 
in their extraction. As soon as the teeth are extracted the head of 
the patient should be raised from the head-rest and the body carried 
forward, and, having a hand cuspidor in front, the patient should be 



— _, Water line 




To gas cylinder 



Sectional view of gasometer. 



requested to eject the blood from the mouth ; this direction is usually 
complied with. The patient in most instances recovers in a few 
moments and with no disagreeable after-effects, but if the ether is 
carried beyond the struggling stage to the point of complete sur- 
gical narcosis the nauseating after-effects are very disagreeable unless 
the patient has been thoroughly prepared for the occasion. 

Nitrous oxid is the anesthetic most commonly administered for the 



USE OF GENERAL ANESTHETICS. 621 

extraction of teeth, and under ordinary circumstances is the best. Until 
lately every operator was his own maker of the gas — this was a great 
disadvantage — but now it can be procured in a liquefied form com- 

Fig. 564. 



Nitrous oxid inhaler. 



pressed in cylinders. There are many different appliances used for 
the administering of this gas even when using it in a condensed form. 
One of the most prominent is that shown in Figs. 562 and 563, in 



622 



EXTRACTION OF TEETH. 



which the gas is drawn into a reservoir and then passes through a flex- 
ible tube to the mouth-piece (Figs. 564 and 565). 



Fig. 565. 




Hood inhaler. 



The two principal mouth-pieces are Fig. 564, which should have 
the detachable lip-shield removed so that the tube may be placed 
directly into the mouth and the lips compressed around the tube by 
the operator, at the same time closing the nostril by the thumb 
and finger, and Fig. 565, which is known as a hood inhaler; it is 



USE OF GENERAL ANESTHETICS. 



623 



Fig. 566. 




Stand for compressed gas cylinder, gas bag, tube, and inhaler. 



624 



EXTRACTION OF TEETH. 



made to cover the nose as well as the mouth. The advantage of the 
first mouth-piece is that the lips may be closely watched for the change 
of color denoting oxygen-starvation of the blood, which the experienced 
operator combats by admitting a certain amount of air with the gas as 
required. Fig. 567 represents a portable appliance to be used at a 
patient's home or away from the regular office. 

Fig. 567. 




Portable nitrous oxid apparatus. 

Dr. Hewitt's Method.— Dr. Frederick Hewitt of London, England, 
has devised the apparatus shown in Figs. 568 and 569. The three 
cylinders contain the compressed gas, two being filled with nitrous oxid 
and one with oxygen. The valves of the cylinders are opened by a key 
which is controlled by the foot of the operator. The tube passing from 
the cylinders to the receiving-bag is double, a smaller tube being placed 
within the outer larger tube. The receiving-bag is also double, being 
divided by a rubber septum into two compartments which have their 
outlet in the double tube which leads to the inhaler. To the receiving- 
bag is attached a mixing-chamber, and to this the inhaling-tube or hood 
is fastened. This appliance is used very successfully in England and 
has been introduced into the United States. It has proved satisfactory 
to all who have tried it. The bags and tubing should be made of 
more durable material when intended for use in the American climate. 



USE OF GENERAL ANESTHETICS. 



625 



The manner in which the appliance is used is as follows : The valves 
in the mixing-chamber (Fig. 569) are closed, then oxygen is let into its 
compartment of the receiving-bag until the latter is nearly filled, when 
the nitrous oxid is admitted into its compartment. The patient being 
prepared, the inhaling-tube or hood is placed in position, and the 
patient is directed to breathe— long, full, and steadily. If the tube is 
used it is necessary to close the nose by the thumb and finger. 



Fig. 568. 




Complete apparatus of Dr. Hewitt for administering mixed nitrous oxid and oxygen. 

The valves are not changed for a few inhalations, during which time 
only air is inhaled ; then, pressing the indicator a downward to the first 
notch 6, the air is cut off, and the patient receives pure nitrous oxid ; 
this is allowed for a few more inhalations, and then the indicator is car- 
ried to the next notch and one part of oxygen is allowed to pass into 
the respiration. When the indicator is carried to the third notch two 
parts are received by the patient, and so on until the maximum amount 
of oxygen required by the patient has been reached. 

It has been found by careful study of many thousands of cases and 
by special scientific investigation that the asphyxia! condition incident 
to most cases of nitrous oxid inhalation is quite unnecessary to the pro- 

40 



626 



EXTRACTION OF TEETH. 



duction of nitrous oxid anesthesia. It is also justly considered to be 
subjecting a patient to an unwarrantable danger to permit the asphyxial 
effect to manifest itself to a profound degree, as in many cases it is 
a menace to life and health, and might have a fatal eifect. The object 
of Dr. Hewitt's method is to control or eliminate the asphyxial element 
by administering a requisite amount of oxygen. 

Fig. 569. 




Showing arrangement of the mixing-chamber, with dial and valve for controlling the 
relative proportions of the gases. 

No fixed rule can be laid down for the quantity of oxygen to be 
added, as each case will require a different amount and this amount 
varies during the several stages of the anesthetic procedure. The 
operator is guided entirely by the symptoms of the patient during the 
administration, his object being to avoid on the one hand the tendency 
toward asphyxia indicated by cyanosis of the lips, and return of con- 
sciousness and sensation on the other hand, which is easily produced 
by an excess of oxygen. By the admixture of oxygen, as in Dr. 
Hewitt's method, the anesthesia is somewhat prolonged over the ordinary 
nitrous oxid method and is slower of induction, but there is entire 
absence of cyanosis, stertorous breathing, jactitation, or any of the 
svmptoms of asphyxia. The modification of the Hewitt apparatus 
that has been lately introduced embodies certain features that make it 
an improvement on the original apparatus. The arrangement of the 
mixing-chamber in reference to the bags containing the gases is such as 
to enable the operator to more accurately control the mixture that is 



USE OF GENERAL ANESTHETICS. 

Fig. 570. 



627 




Apparatus for administering nitrous oxid and oxygen combined: a, key to oxygen bag; b, key to 
oxygen cylinder ; c, gauge showing percentage of oxygen being administered ; d, mixing- 
chamber ; e, key to nitrous oxid cylinder ; /, key to nitrous oxid bag. 



628 EXTRACTION OF TEETH. 

administered to the patient. By a turn of the levers a and / (Fig. 570) 
any gradation of the gases may be obtained, from pure nitrous oxid on 
the one hand to pure oxygen on the other. The construction of the 
apparatus is such as to better withstand the climatic conditions than the 
Hewitt apparatus. A brief description will suffice to show the working 
of the apparatus. 

There are two cylinders, one containing compressed nitrous oxid and 
the other compressed oxygen. 

Two bags, one of black material containing the nitrous oxid, the 
other of red material containing the oxygen. 

The key to each cylinder (see h and e) opens the valve and allows 
the gas to pass into its respective bag. 

By opening the valve (see /) of the nitrous oxid bag the gas passes 
into the mixing-chamber, from which it flows through the covered rub- 
ber tube to the inhaler. 

When it is desired to combine oxygen with nitrous oxid, open 
gauged valve (see a, c) to the oxygen bag ; this will admit the oxygen 
into the mixing-chamber. Both gases will pass through the tube to 
the inhaler. 

The proportion of oxygen used will be determined by the degree 
to which the gauged valve is opened. 

By closing the valve of the nitrous oxid bag, oxygen can be given 
separately. 

Similar results are obtained when air is admitted, instead of oxygen, 
to the patient during the nitrous oxid administration. The details of 
this procedure are set forth in the following chapter. 



CHAPTER XXI. (Continued). 

EXTRACTION OF TEETH UNDER NITROUS OXID 
ANESTHESIA. 

By J. D. Thomas, D. D. S. 



Where the operation would cause excessive pain, the extraction of 
a tooth without the aid of an anesthetic is to-day little short of bar- 
barous. It is cruel to the patient, and if the subject be a child, 
wantonly so. Very few people can submit to the operation without 
more or less physical resistance, and even though this be involuntary 
no operator can do full justice in such a case, no matter how skillful he 
may be. Such resistance causes more or less unnecessary strain to be 
applied in one direction or another against the process, which results in 
increased inflammation as a sequence. Besides, as a rule the liability 
of breaking the tooth or portions of the alveolar plate or other accidents 
is increased a hundredfold. 

Nitrous oxid is in all respects the very best anesthetic for the pur- 
poses of the dentist. Properly used, it is almost entirely free from 
danger and is rarely productive of nausea or depression as an after- 
effect, even temporarily. It seldom requires over sixty seconds to pro- 
duce anesthesia, and in less than that period of time the patient is 
fully recovered, with no knowledge of the operation, and is ready to 
depart as soon as bleeding ceases. To accomplish such a result, of 
course, requires experience and some degree of dexterity, but the con- 
ditions are such that any dentist with a fair amount of experience can 
operate successfully with it for the removal of from one to four or five 
teeth, and perhaps more — the main essential in operating by the aid of 
nitrous oxid being to utilize every second of time during the period of 
anesthesia, and not to waste it in hunting forceps or deciding how they 
should be used. 

The best success is obtained by formulating a system of working by 
which one can accomplish the most in the shortest space of time. The 
operating period seldom extends over forty-five seconds and often less, 
so that every second wasted in any way whatever is so much time lost, 
and success is diminished to just that extent. 

Nitrous oxid must be absolutely pure, and if be kept over water it 

629 



630 EXTR ACTIOS OF TEETH UXDEE XITROUS OXID. 

must be fresh. Id former times when the dentist manufactured his own 
gas, to insure perfect purity it was necessary to test the ammonia nitrate 
before using it for making the nitrous oxid, but at the present day the 
pure gas is made with great accuracy by the manufacturers and is 
supplied chemically pure, compressed in cylinders, so that the individ- 
ual dentist is relieved of the responsibility of manufacturing his own 
gas and of the troubles necessary to secure purity. 

The first essential to success in its administration is a perfect 
inhaler. This should be sufficiently large to permit the patient to 
breathe without the slightest exertion. Patients are always in a more 
or less nervous state upon approaching the dental chair for extraction. 
There is usually accelerated heart-beat and consequently deranged 
respiration, and unless they can breathe through the inhaler with per- 
fect freedom they labor under a sense of suffocation which adds greatly 
to their apprehension and disturbs their equanimity while passing under 
the influence of the anesthetic. 

The inhaler shown in Fig. 565 is perhaps the best one upon the 
market, but has the disadvantage of having hard disk valves, and 
while the size is sufficiently large for most purposes the space between 
the outer circumference of the disk and the inner circle of the pipe is 
so small that it does not at all times permit of free ingress of the gas 
to the lungs, and, besides, such valves are not always airtight. 

The best inhaler is one made of vulcanized rubber turned to the 
proper dimension and fitted with valves made of rubber dam (Fig. 
571). These valves have the property of fitting closely, making the 

Fig. 571. 




Thomas"s inhaler. 



passages airtight, and being flexible they admit the gas to the lungs 
with little or no obstruction. This inhaler is the one employed by 



ADMINISTRATION OF NITROUS OXID. 631 

most operators who make a specialty of extraction, and is made only 
upon special order. 

In giving nitrous oxid it is necessary that the valves of the inhaler 
shall be airtight, for if there is a leakage by which air is constantly 
being admitted, it will interfere greatly with the production of the 
desired results. The hood face-piece should never be used. Aside from 
the impossibility of fitting the face so closely as to preclude the admis- 
sion of some air during the administration, particularly when beard 
exists, it covers the lips from view, and these are an important index 
during the process of anesthesia ; the color of the blood as shown 
through the mucous membrane of the lips should never be lost to 
sight. 

There is no separation of the elements of nitrous oxid at the tem- 
perature of the human body, or during its inhalation, consequently it 
is practically an inert gas so far as its power to support life is con- 
cerned. It possesses strong anesthetic properties but it is also to a 
degree productive of asphyxia, and the color of the lips must be ob- 
served as a guide to indicate the extent to which asphyxia is taking 
place. It has been previously said that the valves of the inhaler must 
be airtight, for a constant leakage of air will prevent the production 
of complete anesthesia, and yet at the proper time during the inhala- 
tion the admission of air, controlled by opening the nose or raising the 
lips, is not only desirable but essential to the proper and successful ex- 
hibition of the anesthetic. 

By the judicious admission of air at the proper time the accompany- 
ing symptoms of approaching asphyxia are obviated and perfect anes- 
thesia is secured without any of the convulsive muscular twitching 
which takes place when the pure gas is given. Dr. Hewitt of London 
advocates the admixture of oxygen with nitrous oxid, for which he has 
introduced the appliances described on p. 624, but by admitting air as 
here suggested similar results are obtained with less manipulation. 

The use of props to keep the jaws open is necessary to insure success. 
They give free scope for operating, and there is no time lost in prying 
the mouth open, as nearly always happens when props are not used. 
Props made of hard wood and of different sizes are the most satisfactory ; 
they should have strings attached, more to reassure the patient than 
for any other reason. Unfortunately, a number of years ago a patient 
died as a result of getting a cork in the larynx, and this has never been 
forgotten. Consequently the string is an assurance to the patient that 
the prop cannot slip down the throat. 

The ordinary dental chair is not desirable for use in administering 
nitrous oxid, particularly those chairs having stationary footstools at- 
tached. Patients are sometimes restless, and every motion made by the 



632 EXTRACTION OF TEETH UNDER NITROUS OX IB. 

feet upon a fixed footstool will produce a responsive movement of the 
body, thereby increasing the risk of accident to the part being operated 
upon. A detached stool upon casters is easily pushed away, so that 
any disposition to move the extremities may be permitted without 
affecting the stability of the upper part of the body. 

This apparent resistance on the part of the patient is not necessarily 
the indication of a knowledge of what is being done ; the upper brain 
function may be paralyzed while the sensory peripherals and motor 
ganglia are not, under which circumstances the patient is not thoroughly 
anesthetized. Resistance may take place at the beginning or just at the 
termination of the anesthetic procedure, and if the operator ceases at 
once the patient will declare absolute unconsciousness of the operation. 
It is, however, sometimes permissible to operate during the stage just 
noted in cases where the systemic conditions are such that it would be 
unwise to carry the patient to the state of profound insensibility. These 
are, however, exceptions and not the rule. To have the exhibition per- 
fectly satisfactory there should be no resistance or outcry. 

A competent assistant is necessary, not only as a protection against 
charges which might be suggested by lascivious dreams — as has occurred 
when ether has been employed (though the period of insensibility under 
nitrous oxid is so short that it would seem that no one, however evilly 
or honestly disposed, could ever sustain such a charge) — but an assist- 
ant can render much aid by holding the tube, lowering or raising the 
head, taking care that the operator does not bruise the lips, holding the 
patient if restless, particularly the hands, and waiting upon the patient 
during recovery from the anesthetic. 

The assistant should be a woman, as it adds very materially to the 
comfort of female patients to have such a person in attendance. 

The operator should receive the patient in such a manner as to 
inspire entire confidence. If necessary, any doubts or possibilities of 
accident should be clearly explained to the patient, so that in the event 
of untoward results there will not be a humiliating sense of failure. 

The patient is seated, and after a careful examination has been made 
and the condition of the tooth or teeth is ascertained, the prop is placed 
where it will be least in the way. The assistant then places the tube 
in the mouth and the patient is directed to close the lips and breathe 
through the mouth instead of the nose ; in the meantime closing the 
nostrils with the third finger and thumb of the left hand, the first and 
second pressing the upper lip about the mouthpiece, while the thumb 
and fingers of the right hand support the lower lip. 

While inhaling the gas it is desirable that patients should breathe 
as in ordinary respiration, for two reasons : First, if instructed to take 
long and deep breaths they exert themselves beyond their natural 



THE OPERATION OF EXTRACTION. 633 

rhythm, and Avith unconsciousness comes involuntary suspension for some 
seconds, and should it occur in one who becomes quickly asphyxiated 
the few seconds of suspension are sufficient to produce alarming symp- 
toms which will require some effort to counteract. Second, if the 
patient breathe slower or less deeply than is natural there is a sense 
of suffocation produced which grows in intensity until unconscious- 
ness supervenes, when the lungs and diaphragm will exert their func- 
tion, producing violent respiratory effort which will be followed by 
marked exhaustion upon recovery. None of these effects need be 
produced if the operator have complete control of the situation. 

No one can explain the symptoms of approaching and complete 
anesthesia in such a manner as will inform a novice sufficiently well to 
undertake the responsibility of administering the gas ; these can only be 
learned through observation and experience, but the first prominent 
indication will be a discoloring of the lips and subsequent pallor of 
countenance, which is not, however, an indication of cardiac depres- 
sion, but is due to the blood color shown through the skin. Should 
the patient be of the blonde and florid type this appearance will be 
more marked, and it is here that the admission of a small amount 
of air is called for, particularly if the blueness seems to approach 
more rapidly than the anesthesia. 

If the pure gas is given to complete narcosis, there will be twitching 
of the muscles of the neck and wrists. Stertor and irregular breathing 
and sometimes decided convulsive action occur, which to one inexperi- 
enced becomes distressing, if not alarming, to behold. 

All these symptoms are at once relieved by air-breathing, and if 
there is a judicious admission of air during the administration of the 
anesthetic they will be avoided entirely. 

The patient being anesthetized — and the instruments being always in 
place so that there will be no delay in picking up the pair of forceps 
required, so that every second of time may be utilized by the work 
in hand — the next step is the extraction. 

The Operation of Extraction. — The proper way to perform the 
operation is to stand in one position, at the right side of the patient, 
during the whole proceeding. For extracting with the greatest facility 
the operator should assume such a position that in standing erect the 
patient's head will be about opposite his upper waistcoat pocket. To 
do this a pair of stools should be used, one just back of the chair and 
erne by the side which may be easily pushed aside when not needed. 
While administering, the operator can stand upon the floor, and ascend 
the stool just before the time for operating. This position is assumed 
by the most successful operating specialists, and is adopted as the result 



634 EXTRACTION OF TEETH UNDER NITROUS OXID. 

of long experience and dictated by the desire to bring about a position 
for work which permits of its most rapid performance and at the same 
time enables the operator to bring to bear the greatest amount of force 
with the least physical exertion. 

When extracting, for example, a lower tooth, and it is necessary to 
force the beaks of the forceps well down through the process, the 
instrument is manipulated by the hand and wrist with the arm held 
closely to the body to steady it. The weight of the body is allowed to 
descend to the proper degree by bending the knees, and when the for- 
ceps are fixed, should force for pulling be required, the straightening of 
the knees will raise the body, the arm being held firmly as described. 
The hand will be used exclusively for manipulating and guiding, while 
the force will be supplied by straightening the knees much the same as 
is applied in lifting weight from the ground. Of course, to become 
expert one must have all of his limbs equally trained. 

In operating on the upper jaw the method is much the same, only 
reversed, bending the knees first to lower the body and forcing the 
instrument to position by straightening and throwing as much of the 
bodily weight upon the arm, by bending the knees, as is necessary for 
pulling. By so doing a tooth will never be allowed to leave the socket 
suddenly as by a jerk, for the operator has perfect control of his hand 
and wrist, and the danger of bruising the opposite teeth in either jaw by 
the forceps is avoided. 

The Forceps. — Seven pairs of forceps are all that are used by the 
writer for extraction in ordinary cases. For the upper teeth, a right and 
left pair for the molars, a bayonet-shaped instrument with the outer beak 
pointed to fit between the buccal roots, and both beaks serrated. In 
working upon both sides of the mouth a pair without pointed beaks may 
be used with advantage to avoid changing. One alveolar pair suffices 
for the roots of all molars and bicuspids on either side. These are 
made bayonet-shaped with smooth concave beaks, but having well 
sharpened edges. The pair for the incisors is straight, with beaks simi- 
lar to the alveolar pair, and when extracting, say all the upper teeth, 
can be used upon all ten front ones with equal facility. 

For teeth in the lower jaw the molar pair is made w T ith both beaks 
pointed, serrated, and gracefully curved so as to bring the force as nearly 
direct as possible; these are equally applicable for all the molars on 
either side and are shaped the same as the alveolar pair. The alveolar 
pair are shaped the same as those for the molars, have smooth concave 
beaks with sharp edges, and are used for all molar roots and bicuspids 
(Fig. 572). The pair for front teeth is curved under the handle and 
may have serrated beaks, as the roots of the lower centrals and laterals 



THE OPERATION OF EXTRACTION. 



635 



Fig. 572. 




Alveolar forceps. 



are so flat that a sharp beak is apt to cut 
them off, if too much grasp is applied. 
They seldom require the force necessary 
in the extraction of other teeth. 

The writer prefers forceps that are not 
nickel-plated, as this imparts a slippery 
or "greasy " feeling to the handle, making 
the hold less secure, which induces an 
increase of force in the operator's grasp, with 
greater liability of cutting or crushing the teeth. 
With forceps having beaks that are not serrated, 
teeth having conical tapering roots will prevent 
the perfect fitting of the cutting edge ; these will 
sometimes slip through the posterior opening of 
the upper or lower alveolar pairs with great force. 
The writer has seen, in one instance, a tooth slip 
through the beaks of an unserrated pair of for- 
ceps and break a pane of glass in front of the 
chair, and an under single molar root which 
shot up with sufficient velocity to penetrate the 
soft palate. 

In extracting, particularly under nitrous 
oxid, no instrument should be used which will 
not securely retain any tooth or root until it is 
safely placed outside the mouth. 

Elevators are wholly out of place when work- 
ing under an anesthetic. They permit no control 
of the root or tooth whatever, and the liability 
of a tooth slipping into the throat under such 
circumstances is too great to warrant the risk. 
The art or " knack " of extract- 
ing does not consist of giving a 
rotary motion to one kind of 
tooth and a lateral or " in-and-out 
motion " to another, but rather of 
" working " the tooth in the socket 
without any pulling until it is 
started or loosened from its at- 
tachment, when the pulling force 
may be applied, and to do this the 
forceps must be placed upon a 
tooth so nicely that the tooth and 
instrument will feel to the hand 



636 EXTRACTION OF TEETH UNDER NITROUS OXID. 

as one continuous object, so that the slightest motion in any direction 
will have immediate effect in " starting " the tooth. The operation is 
completed by continued working while the pulling is applied in the 
direction which will prove the most effective in dislodgment. 

This " working " should be done with as little motion as is possible, 
for the smallest degree of straining upon the process laterally only 
adds so much more distention to the alveolar plates, and increases the 
inflammation and pain after the operation. When nitrous oxid was 
first introduced and extracting was transferred to those who made it a 
specialty, it was noticed that there was less soreness of the mouth follow- 
ing the operation, and it was thought by some that the oxygen of the 
gas produced a beneficial effect upon the blood which caused better 
healing, but such is not the case. 

The object, in extracting, of one who becomes expert by constant 
practice is to save the surrounding parts from all unnecessary strain, 
consequently less pain and soreness follows the operation. There are 
teeth having curved and divergent roots, and cases of exostosis, which 
will require great effort to remove, but even in these the position as- 
sumed and the process of " working " the tooth in the direction of 
the force applied all tend to accomplish the result with less injury than 
would be otherwise produced. 

In this way the breaking of a tooth need seldom occur unless inten- 
tionally. If in extracting an upper or lower molar one finds by the 
extra amount of force required that it will not readily yield, then it is 
better to break the crown off and with the sharp alveolar forceps remove 
the roots separately. This can be done with less injury to the alveolar 
plates than if much greater force were applied to remove the tooth 
as a whole. 

There will be cases of fracture of points of roots which are much 
curved or divergent, but many of these retained fragments may be per- 
mitted to remain until in the process of exfoliation they come to the 
surface if their retention is regarded as likely to give rise to less 
trouble than the injury incident to their removal would cause. But 
these need rarely occur if the operator has by experience acquired that 
sense of feeling which tells him at once the direction of the curve or 
the size of the exostosis. 

Inverted or impacted third molars are the most difficult cases which 
present themselves for extraction. Instead of being surrounded by 
pliable process they are planted in compact bone at the angle of the 
jaw, bound in by the second molar in front and hard bone on the 
buccal side, so that above it in the angle is the only direction offered 
for removal, working them toward the tongue where the bone is 
thinnest. 



THE OPERATION OF EXTRACTION. 637 

In addition to the difficulty in removing these teeth, this severe 
process of pressing the inner alveolar plate toward the tongue excites 
a state of inflammation, easily communicated to the soft tissues of the 
throat, and the after-effects assume in many cases such serious condi- 
tions that it is better practice to remove the second molar. 

If the third molar is sound it may remain and will cause no further 
trouble, as the primary difficulty was caused by crowding and pressing 
upon the second molar ; and should it be necessary, from decay, to re- 
move it, the extraction of the second molar first, renders the operation 
simple and easy of accomplishment. 



CHAPTER XXI. (Concluded). 

LOCAL ANESTHETICS AND TOOTH EXTRACTION. 

By Henry H. Burchard, M. D., D. D. S. 



Prior to the discovery and application of cocain, the local anes- 
thetics employed to produce a condition of analgesia of the structures 
surrounding a tooth to be extracted were sprays of extremely volatile 
substances. Through the rapid evaporation of a spray of one of the 
lighter hydrocarbons, a condition of refrigeration of tissues was brought 
about during which a tooth could be extracted painlessly. Sprays of 
rhigolene and of ethylic ether have been superseded by those of ethyl 
and of methyl chlorid, these substances being more volatile ; directed 
in a fine spray over the gum of the tooth to be extracted, an intense 
local anemia is produced, and as a consequence analgesia results. If 
the refrigeration be rapidly produced and the operation be performed 
promptly upon the attaining of analgesia, the frozen tissues recover 
with but slight reaction. It is to be remembered that the tissues are 
frozen, and if the action be prolonged a condition akin to chilblain is 
present. The mode of application is as follows: All of the mucous 
membrane, except that over the roots of the doomed tooth, is to be pro- 
tected from the spray by means of napkins. The spray is directed 
against the exposed gum, the vial containing the ethyl chlorid being 
held about a foot from the mouth. When the gum becomes intensely 
anemic, indicated by pronounced whiteness, the tooth is to be extracted. 
Ethyl chlorid must be kept in a cool place, and far from any flame ; it 
is inflammable and explosive. 

Preparations containing cocain (benzoyl-methyl-ecgonin) have to 
a great extent superseded all other local anesthetics employed for this 
purpose. It was clearly shown soon after the introduction of this 
alkaloid that its local anesthetic action when applied to the gums did 
not extend beyond the depth of the mucous membrane, so that its epi- 
dermic application does not render the operation, of tooth extraction 
painless. The hypodermatic application was found to render the tissues 
infiltrated perfectly analgesic. A recklessness was evinced in its use 
after this method which was promptly followed by repeated disasters ; 

639 



640 LOCAL ANESTHETICS AND TOOTH EXTRACTION. 

a formidable list of casualties grew. Reports of cases of respiratory 
and of cardiac paralysis following its employment were not uncommon. 
It apparently needed disaster to demonstrate that cocain belonged in the 
category of actively poisonous alkaloids, being by no means the bland 
and safe agent many operators seemed to think it. This lesson, learned 
at great cost, is one the operator is ever to heed, particularly in the 
hypodermatic employment of the agent. Dr. M. H. Cryer has re- 
ported l cases of ascending degeneration of the trunks of the maxillary 
nerves following upon cocain injections about the jaws. 

For the origin, composition, physiological effects, and toxicology of 
the drug the student is referred to the standard works upon materia 
medica. There are several points, however, which cannot be over- 
emphasized, the first being in regard to the drug itself. A full dose of 
cocain hydrochlorid by the stomach is about gr. f . The composition 
of the commercial specimens is not constant ; some of them appear to 
contain the actively poisonous alkaloid isatropylcocain. A safe dose 
when applied hypodermatically is not in excess of gr. j-. 

The lethal effect of cocain is upon the respiratory centre. Its 
absorption is followed by a stimulation of the cardiac and respira- 
tory functions, which is commonly followed by a reaction, the stimu- 
lation giving way to depression. Idiosyncrasies as to the effects of 
cocain are common ; cases of susceptible women have been noted in 
which gr. -| produced toxic effects, It is to be noted that the depres- 
sion following as a secondary effect upon the primary stimulation may 
not occur for an hour or later. 

In prescribing cocain for hypodermatic injection, the analgesic is 
the first element to be considered in the prescription. The dose is not 
to exceed gr. -J-. The second factor demanding attention is a physio- 
logical antidote, one which will not neutralize the analgesic effect and 
yet will prevent the toxic action of the cocain upon the cardiac and 
respiratory functions. Morphin is that agent. As its full physiological 
effect is not required, a small dose, gr. ^ will be sufficient. The next 
ingredient of the prescription is an agent which shall prevent abrupt 
spastic contraction of the arteries and heart. Trinitrin is this agent. 
One drop of the 1 per cent, solution is the indicated dose. 

Fungi develop freely in solutions of cocain, so that if the pre- 
scription is to be a permanent solution, an antiseptic is required to 
prevent decomposition. Cinnamic alcohol answers well for this pur- 
pose. One drop of carbolic acid to each half-grain of cocain is an 
efficient antiseptic. By boiling cocain is split up into methyl, benzoic 
acid, and ecgonin, so that cocain solutions cannot be sterilized by 
boiling. 

1 Proc. Academy of Stomatology, Philadelphia, 1896. 



COCAIN. 641 

The dose commonly employed of the components of the prescription 
is — 

1^. Cocainse hydrochloride gr. -J- ; 

Morphinse sulph., gr. -^ ; 

or Atropine sulph., gr. j^ ; 

Trinitrin. (1 per cent, sol.), gtt. j ; 

Acid, carbolic, gtt. j ; 

Aquse, q. s. 3ss. — M. 

S. The above represents a half-syringeful and is a full dose. 

This solution has been employed with general success, provided 
strict antiseptic precautions have been taken. Untoward results are 
occasionally found even with this seemingly safe formula. 

In the hypodermatic use of cocain the relatively safe maximum dose 
should never be exceeded and the exact amount administered in a given 
case always definitely known. A common error has been the dependence 
upon solutions of a given percentage composition. The danger of such 
dependence becomes evident when it is considered that the safe maxi- 
mum dose of cocain salt may be easily exceeded by the use of a sufficient 
quantity of a low-percentage solution, while on the other hand it is 
quite possible to keep within the limits of safety by using minute 
quantities of a high-percentage solution. The supposed harmlessness 
of a dilute cocain solution is erroneous and misleading unless the factor 
of the absolute quantity of the drug contained in a given amount of 
solution is constantly kept in mind. 

A method which is in all respects safer and which enables the oper- 
ator at all times to know the exact amount of cocain salt injected is to 
make the solution upon the basis of eight grains of the salt to one ounce 
of the menstruum, which will give one grain in each drachm and -^ of 
a grain in each minim. Of such a solution from five to eight minims 
may be injected about a tooth with a reasonable degree of assurance 
that the safe limits of physiological effect have not been exceeded. 

The menstruum in which these ingredients are combined is an inter- 
esting feature. It has been repeatedly shown that the injection of a 
quantity of water will produce anesthesia of a region. The nerve fila- 
ments are compressed by the fluid and do not transmit painful impres- 
sions. 

Dr. Schleich of Greifswald l follows, for the induction of local anes- 
thesia for operations in general surgery, an infiltration method. The 
injection is divided and the punctures made seriatim about the territory 
to be operated upon. The remarkable feature of his procedure is the 
minute dose employed. He uses a 1 : 4000 solution of cocain, to which 

1 T. Parvin, Proc. Phila. Co. Med. Soc, Nov. 13, 1895. 
41 



642 LOCAL ANESTHETICS AND TOOTH EXTRACTION. 

is added l of 1 per cent, sodium chlorid and a small quantity of 4 per 
cent, tricresol. One syringeful, about a drachm, is sufficient to infil- 
trate the tissues about a tooth and render its extraction painless. A 
drachm of the 1 : 4000 solution contains about gr. T ^- of cocain. The 
strongest solution employed by Schleich is a 1 : 500. A drachm of such 
a solution would contain less than gr. ^ of cocain. Dr. W. F. Litch 
(ibid.) has pointed out that low-percentage solutions will give a safer 
result than those of high percentage, even though the absolute amount 
of the drug should be the same. It is seen, therefore, that the quan- 
tity of menstruum in which the dose of cocain is suspended is an im- 
portant consideration. 

Tablets for making Schleich' s solutions may be had of pharmaceu- 
tists. Tablets for making the strong solution contain — 

Jfy. Cocaina? hydrochl., gr. ^- ; 

Morphinse hydrochl., gr. ^ ; 

Sodii chlorid., gr. ^. 
S. Dissolve in Vf[ 100 of distilled water. 

Almost without exception the nostrums advertised and sold under 
high-sounding titles, for employment in this field, contain cocain. 
Neither their names nor any information vouchsafed by their venders 
give any indication of the amount of alkaloid present, and so all of 
them should be tabooed. It is nothing short of criminal to employ 
these nostrums without a knowledge of their exact composition. 

Tropacocain (benzoyl pseudo-tropin) has been employed to render 
the operation of tooth extraction painless. It possesses decided advan- 
tages over cocain. It is only one-half as toxic ; has but slightly de- 
pressant action upon the cardiac ganglia ; has no paralyzant action upon 
the respiration ; anesthesia is more quickly produced, and its solutions 
are slightly antiseptic. Solutions of the drug are made in distilled 
water ; the full dose is gr. \ to -§-. 

The reader, of course, at once draws the correct inference that 
Schleich's method gives promise of safety. Applications made hypo- 
dermatically of the elaborated prescription presented are not without 
danger even in physiological dose. 

It is necessary that the field of operation be made aseptic before 
injection. The mouth should be washed repeatedly with a powerful 
antiseptic, 3 per cent, pyrozone, 10 per cent, electrozone, or 3 per cent, 
formaldehyd solution. 

The syringe should be aseptic ; repeated washing of syringe and 
points in a 25 per cent, solution of phenol sodique will serve this end 
without detriment to the syringe piston or the metallic parts of the: 



SCHLEICH'S SOLUTIONS. 643 

syringe. A syringe having stout finger-rests and holding one drachm 
is employed. The needles should be reinforced for half their length, 
and should have sharp, fine points. 

The gum is to be dried and touched with a 20 per cent, solution of 
cocain ; in five minutes the needle may be inserted painlessly. The 
syringe is filled with the analgesic solution, the needle screwed on, and 
the piston pressed down until all air is expelled from the syringe and 
needle. The latter is now thrust into the gum about midway between 
the neck of the tooth and the apex of the root, until it comes in contact 
with the alveolar process, when it is slightly withdrawn and a few 
drops of the solution are driven into the tissues. A second injection is 
made over the apex of the root ; if the strong solutions be used, the 
amount of fluid injected must not contain more than gr. -J- of cocain ; 
even though several punctures be made. Care must be exercised to 
confine the injection to the tissues of the gum ; if the submucous tissue 
beneath the junction of the cheek and gum be injected into, alarming 
emphysema may result. 

For multirooted teeth an injection is made over each root. If 
Schleich's solution be employed, a full drachm of fluid should be in- 
jected, until the gum over the tooth is tense and white, when extrac- 
tion may be accomplished painlessly. 

In some instances the intense anemia present at the moment of 
extraction may be succeeded by local hemorrhage as soon as reaction 
is established. An antiseptic hemostatic should be applied to the 
alveolus after extraction ; phenol sodique, full strength, is an admirable 
agent for this purpose. 

The imminent dangers to be feared in this connection are : first, the 
toxic effects of the drug. As these are usually manifested in contrac- 
tion of the bloodvessels the antidote is amyl nitrite. A supply of pearls 
each containing tTliij of amyl nitrite should be kept in the medicine 
cabinet. When a patient exhibits great pallor, a small pulse, and bluish- 
white lips, one of these pearls is crushed in a napkin and the nitrite 
quickly inhaled. The conjoint administration of gtt. xx. aromatic 
spirits of ammonia, or about half an ounce of brandy, is advised. 
Should these measures not prove promptly effective, artificial respiration 
should be immediately begun and be prosecuted vigorously. 

The second danger is septic infection, either through imperfectly 
sterilized instruments or by carrying septic organisms from the mucous 
membrane covering the gum into the deeper tissues during the opera- 
tion of injection. This is avoided by a careful sterilization of the 
syringe before it is used, and the repeated applications of antiseptic 
mouth- washes previous to injection. Prescriptions which contain a 
large percentage of carbolic acid are liable to cause sloughing. 



644 LOCAL ANESTHETICS AND TOOTH EXTRACTION. 

Injections forced between the periosteum and bone may produce 
serious injury. 

The introduction of eucain as a local anesthetic was due to the 
observed chemical similarity of that synthetic body with cocain ; an 
instance of presaging the physiological effects of a drug by its chemical 
composition. Its local effect upon bloodvessels is to produce hyper- 
emia, instead of the ischemia induced by cocain. It is less poisonous than 
cocain and its solutions are chemically more stable. Its primary action 
upon the central nervous system is one of exaltation, and this is followed 
by paralysis, the effect being central, not ascending. The sedative 
central influence causes a quickening of the heart-beats through sedation 
of the inhibitory (pneumogastric) nerves. Although eucain is less toxic 
than cocain it also produces a greater degree of analgesia ; so that the 
dose need not be greater than that of cocain, about \ to f of a grain 
being the maximum. 

Eucain may be kept in permanent and stable solution in distilled 
water. A 10 per cent, solution may be made in distilled water (48 
grains of eucain hydrochlorid to the ounce of distilled water) and the 
solution sterilized by boiling, which does not decompose eucain. From 
five to eight minims of such a solution is a proper dose. The precau- 
tions to be observed and the mode of application are the same as for 
cocain. 

Besides the dangers arising from the hypodermatic administration 
of a physiological overdose of this class of analgesic drugs, and the local 
danger of infection from non-sterile solutions or instruments, there is to 
be strongly emphasized the danger of local necrosis due to the poisonous 
effect of the drugs themselves upon the tissue elements when directly 
injected. In nearly all cases in which extraction is sought the tissues 
about the tooth are in a condition of lowered vitality, brought about by 
the local toxemia resulting from the infection which has produced the 
inflammatory process. The injection of a protoplasmic poison, such as 
cocain, eucain, and their congeners, into the inflamed territory causes a 
still further depression of vital resistance, which, if sufficiently pro- 
nounced, may become total and permanent. Hence, tissue-death or 
necrosis, with subsequent sloughing, will necessarily result. 

Where the inflammatory process about a tooth is at all pronounced, 
it is much Aviser to discard local anesthetic methods for the far safer 
procedure of general anesthesia induced by nitrous oxid or ether. 



CHAPTER XXII. 
PLANTATION OF TEETH. 
By Louis Ottofy, D. D. S. 



The transplantation of a tooth signifies the insertion of a nat- 
ural tooth into a natural alveolus other than the one it originally occu- 
pied. The tooth may be an old and dry specimen transplanted into an 
alveolus from which a tooth has been recently removed, or it may be a 
freshly extracted tooth transplanted from one part of the mouth of an 
individual to another part of the mouth of the same individual, or it 
may be a freshly extracted tooth transplanted from the mouth of one 
person into that of another. 

Replantation signifies the replacing of a tooth in the alveolus 
whence it had been removed by design or accident. The operation may 
be performed at once or at any time before the socket is filled with new 
tissue. 

Under the term implantation are included all those operations 
which involve the formation of an artificial alveolus for the reception 
of the root of a human tooth. The operation of altering the size or 
form of an existing alveolus to receive a tooth belongs to this class, 
although it is a combination of trans- and implantation. 

The operation of replantation probably far antedated that of trans- 
plantation, as the latter preceded implantation, but its definite history 
is unknown. It is safe to presume that it has been practiced ever since 
mankind conceived of the natural healing power of the body. Even 
when performed with crudity and without any clear comprehension 
of the mode of repair, favorable results have been reported. The ope- 
ration is at present an uncommon one : the condition for the relief of 
which it was at one time practiced with comparative frequency, chronic 
alveolar abscess, has been found amenable to less radical treatment. 

The operation of transplantation is first noted in the writings of 
Ambroise Pare in the sixteenth century, though credit has generally 
been given to Dr. John Hunter, who gave the subject considerable 
attention. Hunter's experiment of implanting a tooth in the comb of 
a cock is classical. The records of the operation do not exhibit any 

645 



646 



PLANTATION OF TEETH. 



great measure of success attending it. Hunter noted cases of trans- 
plantation of dead teeth which remained for years. 

No one disputes with Dr. Younger of San Francisco the authorship 
of the operation of implantation. The date of his first operation was 
June 15, 1885, although Bourdet in 1780 was the first to mention the 
operation, stating that " irresponsible persons claim to make a socket, 
and implant into it a tooth." An attempt at partial implantation is 
recorded in Dental Cosmos, vol. xix. p. 258. 

In order that an intelligent conception may be had of the intimate 
nature of the biological conditions which surround the teeth after inser- 
tion by either of these operations, it is essential to study the general 



Fig. 573. 1 



Fig. 574. 




1 1 
15 1 

A tooth and its normal attachment and vascular 
supply : 1, 1, Apical pericementum in which 
is seen the main pericemental artery, 5 ; 2, 2, 
anastomosing bloodvessels or channels of 
the alveolar walls ; 3, 3, the marginal anasto- 
mosis of alveolar and pericemental arteries. 




Conditions following replantation: 1, 1', The 
pericementum and inflammatory effusion 
between pericementum and alveolar 
walls ; 2, 2, source of blood-supply to the 
area of repair ; 3, 3, terminations of alveo- 
lar arteries ; 5, obliterated apical artery. 



processes which attend the repair of tissues, and their behavior toward 
foreign bodies. 

As all of these operations are performed under the strictest antiseptic 
precautions, the consideration of bacterial influence is omitted at this 
juncture. As it is impossible to secure specimens which would show 
these several parts in their true relations, the illustrations are neces- 
sarily diagrammatic and theoretical. 

1 Figs. 573-576 are from drawings by Dr. H. H. Burchard. 



BIOLOGICAL CONDITIONS IN PLANTATION 



647 



Fig. 573 exhibits a longitudinal section of an incisor, its attachments 
and support, together with its vascular supply, in its normal relations, 
the bloodvessels from the pericementum anastomosing with those of 
the alveolar periosteum. The pericemental space is filled with fibrous 
tissue. To avoid confusion the nerves and veins have been omitted. 

Fig. 574 represents the conditions following replantation. The tooth 
has been sterilized and its pulp canal hermetically sealed. The perice- 
mental bloodvessels have been destroyed in extraction. Portions of 
the pericementum are seen clinging as fibrous remnants to the cemen- 
tum. The remainder of the alveolus is filled with inflammatory corpus- 



Fig. 575. 



Fig. 576. 




Conditions following transplantation : 1, 1', 
Embryonic tissue which will be organ- 
ized into repair tissue replacing the 
original pericementum ; 5, obliterated 
apical vessels. 




Conditions following implantation : 1, 1, Alveo- 
lar arteries ; 2, 2, gingival margin ; 3, inflam- 
matory still unorganized tissue filling the 
space between the cementum and walls of 
the artificial alveolus ; 4, 4, phagocytes, mul- 
tinucleated cells attacking cementum of im- 
planted tooth ; 5, obliterated apical vessels. 



cles. The vascular supply to the regenerated pseudo-pericementum is 
derived first from the vessels of the alveolar periosteum via the alveolar 
process. 

Fig. 575 shows the conditions existing soon after the operation of 
transplantation. The mechanical violence of extraction has irregularly 
enlarged the natural alveolus. The tooth, its apex rounded, is shown 
with the blunted extremity. The vascular supply is similar to that 
of Fig. 574. The alveolar space is filled with inflammatory corpuscles. 



648 PLANTATION OF TEETH. 

Fig. 576 exhibits the conditions probably existent soon after an im- 
plantation operation. The vascular supply is the same as shown in Figs. 
574 and 575. Instead of having a layer of periosteal bone, the for- 
mation of the artificial alveolus is into the spongy medullary bone. 
The artificial alveolus, being necessarily different in size and outline 
from the tooth, is filled with inflammatory products. Some of the cells, 
becoming multi-nucleated, are seen to be exercising their phagocytic — 
or, in this connection, resorptive — function upon the cementum. 

Replantation and Transplantation. 

Replantation. — In the present state of dental practice the following 
conditions may be regarded as warranting replantation : 

(1) When a tooth has been dislodged by traumatism, a blow by a 
ball, club, or fall, etc. 

(2) When a tooth has been accidentally removed by the slipping of 
the forceps during the performance of a dental extraction. 

(3) When some disease, otherwise incurable, affects either the root or 
some portion of its alveolus. 

The first two causes are practically the most frequent under which 
replantation is justifiable. 

In case a tooth has thus been dislodged and found, it should at once 
be cleansed of all foreign matter and then be carefully examined for 
fractures or other injury. Any cavities present should be filled, the 
contents of the root canal removed, and the space filled in the manner 
described later ; fractured or abraded portions or surfaces are to be made 
smooth, and the tooth placed in an antiseptic solution. A careful ex- 
amination of the socket should then be made. It will be noticed when 
the accident has befallen a young individual, that as a result of the 
flexibility of the bone, the alveolar process is seldom fractured — an 
accident more prone to happen in adult life. 

Some discrimination should be exercised as to the promptness with 
which to replant the tooth. If there is considerable inflammation as 
the result of injury, it is not advisable to immediately replace the tooth. 
In that event the socket should be made aseptic and if possible normal 
hemorrhage re-established. As a general rule several days should be 
allowed to intervene when the inflammation is excessive ; otherwise a 
tooth may be replaced at any time as soon as it has been prepared. 

The governing pathological principle is as follows : Immediately after 
an injury, a certain amount of inflammation takes place and there is 
retrograde metamorphosis — a destruction or breaking down of tissue ; 
and this is not the most favorable time to expect re-attachment to take 
place. As a rule, within a few days a building-up process, constructive 



REPLANTATION AND TEA NS PLANTATION. 649 

metamorphosis, has set in, and the replacement of a tooth at this time is 
likely to be followed by more favorable results. This period sets in at any 
time from three days to a week, the socket being then partially filled 
with active living cells. Just prior to the replacement of the tooth the 
socket and the gum surrounding it having been cleansed and sterilized, 
the tooth itself being brought forth from its antiseptic medium, it must 
be promptly replanted. As a rule, constant but not severe pressure will 
permit the tooth to assume its original position in the socket, although 
sometimes it is necessary to remove a part of the apex of the root or 
slightly deepen the socket by means of a suitably shaped bur. It hap- 
pens occasionally that the location of the tooth and the general surround- 
ings are such that a tooth like this may be retained without any further 
attachment, but as a rule it is not safe to trust to uncertainties regarding 
the attachment of the tooth. An impression of the tooth and its neigh- 
bors can be quickly secured with Melotte's compound or in clay, a die 
is easily made, from which a cap, such as will be described, is quickly 
made. 

It is needless to dwell upon the second cause mentioned. No dentist 
can ever be excused for accidentally removing a sound tooth, but in 
case the accident does happen the above procedure is indicated. 

The opportunities enumerated under the third section are also, for- 
tunately, exceedingly rare. The cases in which formerly replantation 
was resorted to, on the ground that the case was incurable, are now 
much less frequently met with, and when they are encountered they 
often yield to treatment, which is now more clearly understood — such 
as amputation of the root, removal of the necrosed portion of the 
alveolar process, etc. When, however, it has been decided to extract 
a diseased tooth and to replant it, diseased portions of the root should 
be removed and a sufficient time allowed to elapse before replantation 
for the socket and tissues to have assumed a healthy aspect, even if 
this should necessitate the enlargement of the socket. 

In cases of pyorrhea alveolaris, which sometimes has been suggested 
as coming under this class, treatment by replantation is out of the ques- 
tion, provided the case has made sufficient progress to suggest such 
a course. Replantation implies the presence of a socket, and when 
pyorrhea alveolaris has made any great degree of progress, the socket 
is wanting. Hence it is but in rare cases that an attempt to cure by 
this method is justifiable. 

Dr. Louis Jack 1 has recorded marked success in several cases at- 
tending an operation of modified replantation for the cure of some of 
the earlier phenomena of phagedenic pericementitis, notably the common 
malposition due to what has been termed voluntary tooth movement. 
1 See Trans. Academy of Stomatology, 1895. 



650 PLANTATION OF TEETH. 

Transplantation. — There is a broader range for the practice of 
transplantation than either of the other operations treated in this 
chapter. As has been seen, replantation is limited in its application, 
and implantation must, from the nature of the operation, be also con- 
fined to a comparatively circumscribed sphere. 

The operation may be performed at any period of an individual's 
life, although as a rule young, vigorous, and mature adult life offers the 
greatest promise of success. Any socket in any part of the mouth, 
when placed in a healthy condition, is a more or less favorable location 
for the reception of a tooth about to be transplanted. It is true that 
sometimes a socket needs to be enlarged or deepened for this purpose, 
but this is a comparatively simple matter. Before the advent of the 
intelligent practice of crown and bridge work, treatment of diseases 
of the pulp and peridental membrane, the bleaching of teeth, and the 
intelligent practice of orthodontia, transplantation was resorted to as a 
remedy for the correction of many trivial disorders. In the light of 
the present day, transplantation is confined to sockets whence teeth 
have been removed for any cause which could not be remedied by some 
other method of treatment : sockets which remain as the result of the 
loss of teeth from accident of any kind (the lost teeth not having been 
recovered) ; from which roots beyond salvation have been extracted ; 
from which diseased teeth must be removed ; from which roots have 
been removed having carried crowns or having served as abutments for 
bridges until their period of usefulness has passed. 

The same rule laid down for the care of a socket previous to re- 
plantation holds good for transplantation ; namely, that inflammation 
must be reduced, and the tooth transplanted into the socket at a time 
when progressive constructive metamorphosis is taking place. This 
period is stated as usually from three to seven days after the removal 
of the tooth. In instances where considerable disease, such as a chronic 
alveolar abscess of years' standing has been present, even a longer time 
should be allowed to intervene before transplantation. 

Preparation of Teeth for Plantation. 

With the exception of such special directions as are necessary in 
each class of the operations described in this chapter, the following 
general directions are applicable to all cases. 

The Scion Tooth. — For replantation a recently dislodged tooth is 
supposed to be at hand, hence there is a fresh tooth. For transplanta- 
tion it is implied that the tooth is either at hand or about to be secured, 
but in a case of transplantation or implantation the age of the tooth 
may be unknown and indefinite. Teeth have been planted whose age 
and origin have been absolutely unknown, and they have become firm 



PREPARATION OF TEETH FOR PLANTATION. 651 

in their new locations. Nevertheless it seems reasonable to take the 
ground that whenever it is possible, teeth should be fresh and something 
of their previous environment should be known. There are no cases 
on record where disease has been transmitted through the medium of a 
planted tooth, although portions of the early literature of this subject do 
indicate such results. The principal objection to old and dry teeth is 
that, the water having been evaporated, these teeth are almost invaria- 
bly fractured or cracked from shrinkage. When these fractures extend 
to the crown portion, the enamel frequently chips off within a short 
time after the tooth has been planted ; while in some instances the 
entire root has been fractured. Another objection to teeth promiscu- 
ously gathered is that it is seldom possible to find teeth in which the 
crowns are sufficiently perfect to be serviceable and to be presentable 
in the mouth. The crown of a dry tooth permits of but slight altera- 
tion with the grinding stone or sandpaper disk without endangering its 
integrity ; Avhile if it is affected by caries to such an extent as to require 
an extensive operation, the life of the filling is likely to be of shorter 
duration than a similar operation performed on a freshly extracted tooth 
or a tooth with living connections. For this reason it is preferable to 
use only the roots of teeth, attaching to them artificial crowns. This 
permits the selection of a crown suitable in size, color, and shape, and 
which may be ground for articulating purposes — an important matter 
in these cases. 

If therefore an old, dry tooth must be used, let it be carefully 
selected with regard to the absence of checks or cracks or fractures, 
and if it be impossible to secure a tooth with such a crown, let there be 
selected a good root to which a crown, as described later, can be 
attached. 

If a freshly extracted tooth can be secured, even though the crown 
may be slightly carious, the necessary filling operation is advisable, and 
such a tooth should be used, if possible. 

Root-filling. — Roots may be filled either from the apex or through 
an opening or cavity in the crown. Gutta-percha seems to answer all 
the necessary purposes, but for a short distance from the apical extrem- 
ity it is well to fill with gold wire or foil. 

Pericementum. — The theory that the pericementum becomes revivi- 
fied does not seem to be tenable ; at least the proposition that life is 
maintained in the pericementum for any considerable period of time 
after the tooth has been removed from vital attachment is not in accord 
with general physiological laws, although periosteum as a tissue main- 
tains its vitality for a time after separation. 1 For the purpose of secur- 
ing an attachment there is no necessity for the presence of the perice- 
1 See Ziegler's General Pathology. 



652 PLANTATION OF TEETH. 

mentum ; but it is reasonable to assume that the nearer to natural states 
the root and the socket are in, the more favorable will be the prognosis. 
It is therefore a safe rule to follow, to preserve as much of the perice- 
mentum as is possible. The preservation of the pericementum has an 
advantage from the fact that after the tooth has been planted, the peri- 
cementum under the influences of bodily heat and moisture expands 
and thus acts in the nature of a sponge graft, enabling the tissues to 
more quickly obliterate spaces which are present and to attach them- 
selves to the root. 

Subsequent Care of Planted Teeth. — Numerous methods for the 
retention of planted teeth have been recommended by various authors 
at different times. While many of them are original and ingenious, all 
are to be condemned except those means which look to the firm, rigid, 
immovable retention of the planted tooth for a definite period, that of 
surgical repair. Neither the rubber-dam splint, silk ligature, nor gold 
or other metal wire comes under this heading. Planted teeth must be 
retained immovably for a period of two to six weeks, occasionally from 
two to eight, ten, or twelve weeks. The shortest time of immobility 
consistent with subsequent attachment is preferable. The tooth to be 
transplanted or implanted should be fitted after preparation in a model, 
made from an impression of the gum where the tooth is to be planted 
and of the adjoining teeth, as shown in Fig. 577. 

An impression is then taken of it and of the adjoining teeth on each 
side. A retention cap is then swaged to cover the grinding surfaces 
of three or more teeth, half the length of the crown on the labial surface 
and nearly the full length on the lingual or palatal surface, as shown 
in Fig. 578. 



Fig. 578. 





Model showing prepared tooth in place : Model showing retention cap 

a, Gold filling at cervical joint. in situ. 

The cap may be made of pure gold, platinum, or German silver. 
The gauge, according to the metal used, should be from No. 32 to 
No. 38. This cap is cemented upon the crowns adjoining the planted 
tooth in such a manner that it may be removed without disturbing the 



PREPARATION OF TEETH FOR PLANTATION. 653 

planted tooth. The operator can remove the cap by springing the 
metal away from the teeth, examine the condition of attachment of the 
planted tooth, and replace the cap if it should be necessary. Where 
the articulation interferes with the retention of the cap, the latter may 
be ligated to the adjoining teeth in addition to being cemented to them, 
and still admit of removal without disturbing the planted tooth. There 
is at present no method of ligaturing or banding the teeth which will 
permit removal of the ligature or band without more or less disturbance 
of the planted tooth. 

Aside from the necessity of immobility for a certain period, the 
planted tooth and surrounding tissue generally require but little atten- 
tion. In occasional cases the tissues may be stimulated, by painting 
the gum with a mixture of equal parts of tincture of aconite root, 
chloroform, and iodin paint (the latter is a saturated solution of iodin 
in alcohol), or by the use of stimulating mouth-washes, notably those 
containing capsicum. The patient should be cautioned to encourage 
the downward growth of the gum by the use of the toothbrush, to 
prevent the accumulation of remnants of food or saliva, and to pre- 
vent their subsequent putrefaction should particles become unavoidably 
lodged around the tooth or cap. This is best accomplished by using a 
camel's-hair brush dipped in hydrogen clioxid or pyrozone, electrozone, 
meditrina, etc., washing out the interstices frequently. A syringe or 
spray from an atomizer may be used. 

Artificial Roots. — Experiments have been performed looking 
toward the use of roots other than those of natural teeth. Eoots made 
of ivory, corrugated or perforated porcelain, lead, gold, platinum, and 
other metals have been used. The writer's experiments in this direc- 
tion have all resulted in failure. There is no recorded evidence that 
any have resulted successfully. 

Mode of Attachment. — As to the mode of attachment of planted 
teeth the subject is clouded in obscurity. From the nature of the con- 
ditions it is difficult to secure definite information. Dr. Younger holds 
to the belief that the pericementum becomes revivified and hence the 
attachment is almost physiological. Others maintain that the filling 
of the space around the root of the tooth with compact bone tissue 
is sufficient to account for the retention of the tooth. In the appear- 
ance of planted teeth which have failed there should be found the best 
illustrations of the causes of success. It is probable that a planted 
tooth, by reason of the absence of the cushion formed by the living 
pericementum, causes more or less irritation in the socket; that this 
irritation leads to resorption of the root; that in this resorption and 
ihe subsequent filling up of these resorbed surfaces are found reasons 
for the success of the operation. Fig. 579, at a, a, shows how a par- 




654 PLANTATION OF TEETH. 

tially resorbed root may be retained in place. The length of time 
during which a planted tooth is retained depends entirely upon the 
rapidity of the resorptive process and the activ- 
Fig. 579. ity of the tissues in maintaining a healthy con- 

dition. Replanted and transplanted teeth have 
been known to do good service for from twenty 
to forty years. The time of the observation as 
to implanted teeth is shorter, the oldest cases 
being less than twelve years old. In the writer's 
observations, extending over a period of nearly 
ten years, a number of teeth have been noted 
An implanted tooth in which have been retained successfully for that 
situ.- a, a, excavations of period; how much longer they will remain ser- 

the cementum due to re- . , , , , n .,, 

sorptive process. viceable, and what percentage ot success will 

attend later cases, will require further time to 
determine. Dr. Younger has had successfully implanted teeth under 
observation for eleven years. 

Precautions. — There is no special danger connected with any of the 
operations described in this chapter, provided the usual antiseptic pre- 
cautions are observed and dangerous anesthetics avoided. Aside from 
these, during the operation of replantation and transplantation no 
special skill is necessary ; certain precautions are, however, essential. 
Inasmuch as implantation is an essentially esthetic operation, it should 
be borne in mind that it is confined principally to the ten anterior teeth, 
and that it is more frequently performed in the upper jaw than in the 
lower. The territory involved is therefore limited. The operator who 
contemplates forming in this territory a socket for the reception of the 
root of a tooth should be intimately acquainted with the anatomical 
and histological relationships of the various parts. 

In the first place it should be remembered that Avhere alveolar 
resorption has taken place, the relative depth of bone is considerably 
less than where a tooth is still in situ and surrounded by the abnormal 
alveolar process. The operator must therefore not penetrate deeper 
into the bone than the original depth of the socket may have been. 
Indeed, it is not as a rule necessary to penetrate so far. 

In the upper jaw the principal danger in making a socket for the 
reception of central incisors lies in the proximity, posteriorly, of the 
anterior palatine nerve, artery, and vein, which have their exit from the 
bone through its foramen, often near the roots of these teeth. With 
the lateral incisor the principal precaution necessary is the preservation 
of the labial plate of the alveolus. If the lost tooth has been absent 
for some time, and much resorption has taken place, it is sometimes im- 
possible to drill a socket so that the tooth has a proper direction and 



PREPARATION OF TEETH FOR PLANTATION. 655 

prominence in the arch, and vet be able to secure a bone covering for 
its labial surface. As a rule there is sufficient process in the canine 
region to enable the operator to secure all the attachment desirable. 
The bicuspid and molar regions present the danger of perforation of the 
floor of the maxillary sinus, This is liable to happen anywhere from 
the first bicuspid to the second molar. Extreme caution should be ex- 
ercised to avoid it. In two instances in practice the perforation was fol- 
lowed by no unpleasant complications. Care was taken not to infect the 
sinus, the teeth were implanted in the usual manner, and the cases re- 
sulted successfully. Subsequently one of these teeth was lost, but dur- 
ing the process of root attachment or encystment the perforation into 
the sinus was closed. 

In the lower jaw the principal difficulties encountered are the follow- 
ing : In the incisive region there is a deficiency of alveolar process, and 
hence much difficulty is encountered, at times, in securing a sufficiently 
deep bony socket. At the location of the canine tooth the lower jaw- 
becomes broader and there is usually sufficient room to enable the 
making of a good socket. In the bicuspid region the principal pre- 
caution necessary is in regard to the mental foramen. It must be borne 
in mind that normally the exit of the nerves and vessels at this point 
is directly below the second bicuspid tooth and that when resorption of 
the alveolar process has taken place this foramen is often near the upper 
border of the jaw. From this point posteriorly implantations are rarely 
performed, and when done the principal precaution must be in regard 
to the inferior dental canal, which is near the surface if much resorp- 
tion has taken place. 

Artificial Crowns. — The precautions necessary in the selection of 

a tooth for transplantation or implantation have been noted, and it 

might be proper at this time to describe the prepara- 

,. n l / .., ..« . , • a * Fig. 580. 

tion oi a root with an artificial crown, presuming that 

it is only in rare instances that a suitable entire 

natural tooth can be obtained. Attention was called 

to the necessity of securing asepsis of the root, and 

the filling of the root-canals has been described. The 

most suitable form of crown has been found to be the 

Logan, which is ground to suit the occlusion and Natural root with 

, . artificial crown. 

cemented into the root canal without much regard as 
to a careful fit at the cervix of the crown to the root. After the 
cement has hardened, the margin between the root and crown is pre- 
pared with engine burs, and a filling of gold introduced, making a 
circle around the tooth. When this is polished down there is a 
perfect gold filling level with the root and crown, which is preferable 
to a soldered band. (See Fig. 580.) 



656 PLANTATION OF TEETH. 

General Considerations. 

Asepsis. — The operations described in this chapter must always be 
performed under perfect aseptic conditions ; that is, the hands and 
person, instruments and other accessories, the tooth about to be planted, 
and the field of surgical operation, must be maintained in a clean, 
aseptic condition. 

Any of the usual, accepted methods can be resorted to. As a rule, 
however, the drugs selected for this purpose should not be of an irri- 
tating nature. For the hands and person, pure soap followed by a 5 
per cent, solution of carbolic acid is sufficient. The instruments and 
other accessories can be kept free from inoculating bacteria by the use 
of pyrozone, formalin, euthymol, or a 5 per cent, solution of carbolic acid. 
The use of bichlorid of mercury in the proportion of 1 part to 2000 of 
water is also permissible, although it is not as advisable on account of 
its irritating nature. The sterilization of the tooth about to be planted 
differs according to circumstances. A tooth whose source is unknown, 
and which has been kept in a dry state for a long period, will not be 
benefited by being placed into an antiseptic solution until just prior to 
the time when it is to be used. Hence dry teeth can be kept in any 
clean box covered with clean cotton until they are ready for use. After 
the necessary preparation hereinafter described, the dry tooth should be 
placed in a solution of glycerol and carbolic acid (about 5 per cent, of 
the latter), and just before using, it can be placed in a pyrozone solu- 
tion or in a solution of carbolic acid and water. Freshly extracted teeth 
should, of course, have their pulp chambers and root canals cleansed 
and hermetically sealed, and then be placed at once in fluid, preferably 
in glycerol to which a few drops of carbolic acid have been added. 

The field of operation may be quickly sterilized and cleansed of 
^adhering mucus by mopping the surface with a ball of cotton saturated 
with hydrogen dioxid 3 per cent, solution just previous to operating. 

It is, of course, of exceeding importance that the socket into which 
a tooth is about to be planted shall be free from disease germs or 
bacteria. As a general rule flowing blood is the best of antiseptics, 
washing away any bacteria which may become lodged from external 
sources, hence so long as a socket is constantly being filled with flow- 
ing blood during an operation, but little further care need be bestowed 
upon it. As a general rule the socket and the tissues surrounding it 
will react more quickly after operation the less the medication has been ; 
hence the very slightest and mildest of antiseptics are indicated. Zinc 
chlorid 2 to 5 grains to the ounce of lukewarm water, hydrogen dioxid 
3 per cent., or the 5 per cent, solution of carbolic acid in lukewarm 
water, give most satisfactory results. These solutions will be found 
quite sufficient to maintain the field of surgical operation aseptic. 



GENERAL CONSIDERATIONS. . 657 

Anesthesia. — For the purpose of allaying pain, the use of anes- 
thetics is justified when imperatively demanded, but unfortunately, in 
the plantation of teeth the benefits derived are frequently outweighed 
by the disadvantages accruing from their use. 

Anesthetics are either general or local. An operator would scarcely 
be justified in assuming the risks attendant upon the use of chloroform, 
ethylic ether, ethyl bromid, or any of the combinations in which these 
anesthetics are administered. Nitrous oxid would, in the majority of 
instances, be contra-indicated by reason of the shortness of the period 
of anesthesia which it induces. 

There do not appear to be any records of satisfactory results with 
hypnosis. That field is open to the intelligent investigator whose 
inclinations lie in that direction. Local anesthesia, therefore, is the 
means generally employed. The use of cataphoresis with local anes- 
thetics has not as yet been satisfactory for this purpose. 

The method adopted has usually been confined to the injection or 
other introduction of cocain, the dose being variable, but usually about 
5 to 15 minims of a 4 per cent, solution of the hydrochlorid. A seri- 
ous objection has been noted to injection through the gum, viz. that 
more or less sloughing or destruction of the tissues may result, and this 
is very unfavorable for subsequent success. In replantation or trans- 
plantation, sufficient anesthesia is often obtained from the wash used in 
cleansing the socket ; but in implantation the formation of the new 
socket is often an exceedingly painful operation, and in these cases 
good results may be had by dipping the instrument with which the 
socket is being made, into crystals of cocain, and thus by the friction 
of the instrument rubbing it into the parts that are being operated 
upon. 

The subject of anesthesia may be dismissed with the sole injunction 
that its use should be resorted to only in those instances where it is 
absolutely necessary. The majority of the cases of plantation are per- 
formed with no more pain than is inflicted in filling operations. 

The same care should be given to the retention of transplanted 
teeth as is given to the retention of replanted teeth. Teeth thus 
carefully transplanted, in individuals of good health, often remain as 
useful members for a number of years. In the past insufficient atten- 
tion has been given to asepsis, and this, coupled with the fact that the 
root had not always been properly filled, has not resulted in as much 
success as is attained with present methods, and yet transplanted teeth 
are known to have remained in a healthy and serviceable condition 
for from twenty to forty years. 

42 



658 PLANTATION OF TEETH. 

The Operation of Implantation. 

Implantation, in order to yield the best results, should be confined 
to mouths which are habitually clean and free from disease, and to a 
part of the individual's life during which the power of the developed 
mental processes is not impaired. Unclean personal habits, the ex- 
cessive use of stimulants, and occupations calling for an unusual ex- 
penditure of nerve force are unfavorable. A suitable case having been 
selected, an impression of the space and of the teeth adjoining it is 
taken. A plaster cast is made, the proper-sized socket drilled therein, 
the tooth is selected and prepared, either with or without an artificial 
crown in the manner previously described, the occlusion is adjusted, 
and a retention cap is made. These preliminaries having been satis- 
factorily accomplished the case is ready for the operation. Under the 
heading of General Considerations the question of anesthesia has been 
already treated. 

The first step in the operation is the making of an incision through 
the gum tissue. A number of different kinds of incisions have been 
recommended by different operators, nearly all of them looking toward 
the preservation of the largest amount of gum tissue. Some recom- 
mend a crucial incision X, turning back the four corners of the gum 
tissue. Others have recommended an incision in the shape of the letter 
H, turning back the two flaps thus made. 

The principal objection to all of the incisions recommended lies in 
the fact that they all look toward the preservation of the gum tissue 
equally for the labial and lingual surfaces ; while, as a matter of fact, if 
proper provision is made for the protection of the cervical line on the 
labial surface, the lingual surface will take care of itself, for it will be 
noticed in cutting through the gum tissue that it is much thinner where 
it- reflects over the alveolar border upon its labial aspect than upon its 
lingual. Hence, frequently, if no attention whatever has been paid to 
the retention of gum tissue on the lingual surface, the neck of the 
tooth will nevertheless be sufficiently protected. 

Fig. 581. 





Incision in gum for implantation. 



Another serious objection to an incision which leaves two or more 
points or margins to be preserved, is that the tenacity of the gum tissue 



THE OPERATION OF IMPLANTATION. 



659 



Fig. 582. 



n 




Chisels. 



N 



makes it utterly impossible to preserve these various flaps and projec- 
tions intact from the cutting instruments. 

The writer's method consists in an incision resulting in one flap, 
with a view of protecting the labial surface of the tooth to p IG 533 
be implanted, and of preserving this single flap from in- 
jury during the progress of the operation. A combina- 
tion, or rather a modification, of the most suitable incis- 
ions recommended is therefore the one shown in Fig. 581. 
This incision is made with ordinary chisels as shown 
in Fig. 582, cutting with the chisel to and 
including the periosteum, lifting it for- 
ward and holding it out of the way of 
the operator by means of an instrument 
similar to the one shown in Fig. 583. 

The operation thus far is usually sim- 
ple and as a general rule not very pain- 
ful. The drilling of the socket varies 
with different individuals according to 
the density of the bone, the length of 
time that the tooth has been out, etc. 
In some instances the reamer or trephine or knife pro- 
gresses rapidly, while in others progress is very slow, or 
sometimes variable as the instrument enters into medul- 
lary spaces or passes through the more or less dense parti- 
tions which divide these medullary spaces from each other. 
The operator will determine during the operation, by 
the progress he is making with different instruments, 
Avhich are the best to use. In some instances the entire 
socket can be made with an ordinary engine bur, while 
in others the strongest instruments especially designed for 
implantation are none too strong. In some instances an 
instrument which clears itself well during one operation 
clogs annoyingly during another. It is desirable to de- 
scribe at this point the various useful instruments which 
have been designed and are now upon the market. While 
all of them are not necessary, some one or more of each 
class are indispensable. The trephines of Dr. Younger, 
of San Francisco, which have been improved by Dr. W. 
W. Walker of New York, have (as shown in Fig. 584), a 
set-screw collar, also shown detached, which slides on the 
shank and is first fixed by a set-screw as a gauge of the 
length of the tooth root. As will be noticed the trephines 
cut only on the edge, and hence they do not entirely clear themselves \ 



11 



Instrument for 
holding flap 
during the 
operation. 



660 



PLANTATION OF TEETH. 



the reamers described on a previous page are then used to remove the 
core and enlarge the socket. 



Fig. 584. 

o OOO 



Fig. 585. 





Younger- Walker trephines. 



Rollins' spiral 
knives. 



The spiral knives (Fig. 585) devised by Dr. W. H. Rollins of 
Boston are in many cases very useful. 

They are also open to the objection of clogging. As an improve- 
ment upon these the spiral crib knife shown in Fig. 586 has the 
advantage of permitting the core to pass within it. 



Fig. 586. 



Fig. 587. 





Ottofy spiral 
crib knife. 



Two forms of Cryer's 
spiral osteotome. 



12 3 4 5 

Ottolengui's reamers. 



Dr. R. Ottolengui, of New York, has devised a set of reamers (Fig. 
588). There are nine leaves to each reamer and each leaf is divided 
into five teeth. Three of the leaves reach the apex of the cone point 
and thus allow a more rapid forward drilling into the bone. A sliding 
collar forms a gauge to indicate the proper depth to drill. 



THE OPERATION OF IMPLANTATION. 



661 



The reamers designed by Dr. Younger, illustrated in Fig. 589, are 
also very suitable for this purpose. Dr. Oyer's spiral osteotome — two 
forms of which are shown in Fig. 587, one with dentate edges the other 
without — is an admirable instrument for forming the artificial socket. 

When it is necessary to deepen or alter the shape of the socket, it is 
done very simply with either the ordinary burs of the dental engine or 
what is preferable, a bur with a long shank such as shown in the 
accompanying illustration (Fig. 590). 

Fig. 590. 




u 

12 3 

Dr. Younger's reamers. 



12 3 4 

Engine burs with long shank. 



The following are to be recommended : Nos. 1 and 3 of the Walker- 
Younger trephines, Nos. 1 and 3 of the Younger reamers, Nos. 1 and 
2 of the Rollins spiral knives, Nos. 1 and 2 of the Ottofy spiral crib 
knives, and Nos. 1, 3, and 4 of the Ottolengui reamers and Cryer's 
osteotome. 

During the progress of the drilling of the socket, the tooth should 
be frequently inserted until a proper adjustment has been secured. 
Occasionally these teeth can be implanted and so perfectly fitted that it 
is almost impossible to remove them with the unaided fingers ; while at 
times the bone is so cancellated, and the tissues so flabby, that a socket 
drilled never so carefully will not retain the tooth in place. Nothing 
is gained by a too close adjustment of the root, as pressure must un- 
doubtedly be exerted, and pressure causes resorption, and may be fol- 
lowed by inflammation. A fair, moderate fitting of the root is all 
that should be aimed at. Just before the final adjustment the socket, 
gums, tooth, and all parts contiguous thereto, should be placed in an 
aseptic condition and the cap adjusted in the manner before described. 
Though the tooth may be adjusted to its socket so that immediately 
afterward it exhibits much firmness, yet in a few days subsequent to 
the operation it invariably shows less rigidity and an apparent tendency 



662 PLANTATION OF TEETH. 

to loosening. This result is probably due to the resorption of those 
areas of contact between the tooth and its artificially formed alveolus 
where the greatest amount of pressure is exerted. The period of 
loosening is generally quickly followed by a progressively increasing 
firmness and immobility of the tooth caused by calcification of the 
exudate thrown out by the walls of the alveolus in the process of repair 
of the surgical injury to which it has been subjected by the operation. 
Planted teeth, when lost, are lost as a rule as a result of resorption of 
their roots. The process seems analogous to the resorption of the 
roots of deciduous teeth. Present records seem to indicate that re- 
sorption of the roots is slowest in progress in replanted teeth ; it is 
more rapid in transplanted teeth, and most rapid in implanted teeth. 
Intelligent observation over replantations and transplantations extends 
from twenty to forty years. The observation of Dr. Younger of 
implanted cases extends at this writing to about twelve years, and he 
has had successful cases under observation which have remained in the 
mouth over ten years. The writer has the records of cases which have 
remained and done good service for ten years. 



CHAPTER XXIII. 

MANAGEMENT OF THE DECIDUOUS TEETH. 

By Clark L. Goddard, A. M., D. D. S. 



Eruption. — The first operation the dentist is called upon to perform 
for the deciduous (temporary) teeth is lancing the gums as an aid to 
eruption of those organs. This is not necessary in normal but only 
in pathological cases. Although gum tissue in its normal condition is 
comparatively insensitive, when it is inflamed it is exceedingly tender. 

The principal source of pain, however, is not in the tissue overlying, 
but when a tooth, bound down by the dense gum tissue above it, by its 
own growth presses upon the formative organ below, it causes pain 
which in many cases may be so excessive as to cause reflex disorders 
of alarming character. 

Dr. J. W. White l says : " The manifestation of functional inharmony 
from pathological dentition will depend, as in trouble arising from any 
other disturbing cause, upon the temperament and health of the child, 
its dietetic management, and its hygienic surroundings. In some cases 
there is a gradual development of biliary, gastric, enteric, and cerebral 
complications, a slow but steady loss of vital power, with no effort at 
recuperation and feeble resistance to the undermining influences which 
gradually but surely wear out the young life. 

" In other cases the indications of disturbance of function are mani- 
fested primarily in the nervous system : the symptoms are all charac- 
teristic of acute derangement and are dangerous from their violence 
and uncontrollability. High fever, vomiting, choleraic diarrhea, men- 
ingitis, convulsions, stupor and death are the rapidly succeeding 1 
phenomena. Between these two phases there is every conceivable 
grade of symptoms, every imaginable complication." 

By many, as an objection to lancing the gums it has been urged that, 
in case the tooth does not erupt immediately, cicatricial tissue is formed 
over it which will bind the tooth down more rigidly than before. Cica- 
tricial tissue is, however, of a lower degree of organization than normal 
tissue, and is more easily broken down. 

1 Amer. System of Dentistry, vol. iii. p. 327. 



663 



664 



MANAGEMENT OF THE DECIDUOUS TEETH. 



Fig. 591. 



The indications for interference are not so much local as general — 
the fretfulness, inability to sleep, and other symptoms mentioned by 
Dr. White. The gum tissue over the erupting tooth may or may not 
be highly inflamed, but the absence of such inflammation 
does not contraindicate lancing. In fact some of the 
gravest systemic disturbances occur where no local mani- 
festations are evident. 

The object is to divide the gum tissue which binds 
down the tooth and to allow it free egress. The most 
suitable instrument is shaped like that shown in Fig. 591 
and sometimes used for lancing around teeth before ex- 
traction. It should be held like a pencil in writing, so 
that one or more fingers can form a rest and guide. 

For operating on the lower jaw the child is best seated 
in the lap of the operator with the head against his breast. 
By passing the left arm around the infant's head and in- 
serting the left thumb in its mouth with the fingers under 
the chin, the lower jaw can be held rigidly while the right 
hand performs the operation. 

For operating on the upper jaw it is best to lay the child 
across on the nurse's lap. The operator takes the head on 
or between his knees, opens the mouth by inserting one or 
more fingers of the left hand, and holds the thumb and 
forefinger on each side of the alveolar ridge, thus prevent- 
ing injury to contiguous parts during possible struggles 
of the child. 

For incisors a simple longitudinal incision is made, a 
little longer than the cutting edge of the tooth. The 
lancet should be sharp, so as to easily penetrate to the 
tooth. No harm will be done except to the blade of the 
lancet. For the canines a single incision is good, but a 
crucial incision is better. Sometimes lancing is necessary 
for the canine after it is partially erupted, as the gum 
tissue, pierced by the point only of the tooth, may form a 
dense ring around this point and interfere with further 
eruption. In such a case a division of this ring in two or 
more opposite places will give relief. 

For the molars a crucial incision is best, one cut ex- 
tending from the posterior buccal to the anterior lingual 
cusp, and the next from the posterior lingual to the ante- 
rior buccal. Sometimes lancing is necessary for these 
teeth after partial eruption. After the cusps have pierced the gum, 
the tooth may be held back by the bands of tissue in the sulci. In 



Gum lancet. 



ERUPTION AND DURATION. 665 

such cases division of these bands in the same direction as before de- 
scribed for an unerupted tooth will give relief. Sharp-pointed curved 
scissors are well adapted to this latter operation. 

Fig. 592 will illustrate the direction of the incisions described. The 
relief afforded is generally immediate. In one case a child who had 
been fretful for several days, and who had not slept at all during the 
day, was asleep in the writer's arms within five minutes after the ope- 
ration. The gum tissue is not very 
sensitive, so the operation is often 
painless. The little sufferer will 

often recognize the relief obtained \T/"S 

and point to other portions of the ^\/^ 

gums for further relief. 

Duration of the Deciduous 







Teeth. — The importance of filling s 
cavities in the children's temporary 
teeth is often overlooked, even by 

dentists themselves, as these teeth are Lines of incision in lancing : a, a, over the 

t -i i i molars ;b,b, over the canines and incisors 

Supposed tO be lost SO early as to before eruption . c , c , c, over the molars 

render such Operations Unnecessary. and canines after partial eruption (J. w. 

r™ • • it • i t • White). 

lhis is generally true with the in- 
cisors, is less true with the canines, while the molars often need at- 
tention. Fig. 541 (see Chapter XXL) shows the relations of the 
deciduous to the permanent dentures in a child of about six years 
of age. A study of the following table will show that while the 
incisors are superseded early by their successors the molars are in 
place nearly twice as long : 

Time of Eruption. Loss. Duration. 

Central incisors 6-8 months. 6th-7th year. 5 J to 6 1 years. 

Lateral 7-9 " 7th-8th " " " " li " 

First molars 14-16 " 9th-10th " 7£ " 9 " 

(1 yr. 2 m.-l yr. 4 m.) 

Canines 17-18 " flnf. 8th-10th " 

(ljyrs.) lSup.llth-12th " 7 " 10 " 

Second molars 18-24 " 12th-13tk " 10 " 11" 

(1^ yrs.-2 yrs. ) 

The temporary molars should be preserved for three reasons : 

1st. To prevent the child suffering pain. 

2d. To allow proper mastication of food. 

This latter is of extreme importance, as these years are especially 
important ones in the child's growth. If he is prevented by pain from 
properly masticating his food it will not be assimilated, and a habit of 



666 



MANAGEMENT OF THE DECIDUOUS TEETH. 



swalloAving food without masticating may be continued even when the 
permanent teeth have erupted. 

3d. To preserve the fulness of the arch for the permanent teeth. 

Early loss of the deciduous second molar will allow the first per- 
manent molar to move forward and occupy room that should be pre- 
served by the bicuspids. Early loss of the first temporary molar will 
allow the second temporary and the first permanent molar to move 
forward. 

The crowns of the temporary molars are much larger than the 
necks, and caries of the approximal surfaces will allow them to crowd 
together with the same result. Approximal fillings inserted should be 
so shaped as to preserve the original contour. If the first permanent 
molar thus moves forward of its natural position a smaller arch is left 
for the successional teeth. The result may be a constricted arch, a 
pointed arch, upper protrusion, or the labial displacement of the 
canines. 

Fig. 593. 1 




10 





ii ;ti »■+-* jXJT 9 " 



Decalcification of the deciduous teeth. The numbers indicate years. 

Odontalgia. — The first visits by children are usually for the relief 
of " toothache," and may occur at any age from two years upward. 

The first treatment of most children's teeth should be palliative. 
In many cases a fear of the dentist has been engendered, which it should 
be the prime object to remove. Make the acquaintance of the little 
patient in the reception room, talking perhaps of things altogether 
foreign to the case in hand, and distract its attention. If the child is 
very timid examine the teeth while it is seated in an ordinary chair, or 
in its parent's lap, and apply some dressing to relieve the pain. 

In the operating room the chair should be adjusted to its smallest 
size ; a special child's seat may be used, or a cushion half the size of the 
chair seat, and not too soft. The child's head should be made comfort- 
able in the head-rest. The operator should not let the child detect him 
in an endeavor to hide instruments ; the necessary ones may be shown 
to him if they arouse his curiosity, and their purpose explained. 
1 Prof. Pierce in Amer. System of Dentistry, vol. iii. p. 639. 



ODONTALGIA. 667 

On account of the difficulty the child has in making himself under- 
stood, or from his not knowing what he wishes to describe, diagnosis is 
difficult. A child cannot always distinguish just where pain is felt, nor 
always remember its exact location. In most cases the first occurrence 
of pain is during mastication. 

It is necessary to ascertain whether pain is caused by an erupting 
tooth, a nearly exposed pulp, a pulp inflamed and dying, a putrescent 
pulp, or an alveolar abscess. If the nearly exposed pulp is suspected, 
test it by the application of a drop of cold water. Pain during masti- 
cation may be caused by thermal changes, by pressure of food in the 
cavity, or by pressure on a tooth whose pericementum is inflamed. 

If the tooth is aching while the child is in the chair, syringe out the 
cavity with warm Avater, dry it with bibulous paper, and apply a pledget 
of cotton saturated with oil of cloves, campho-phenique, or whatever 
has been found effective with permanent teeth. Fletcher's carbolized 
resin l has been invaluable for this purpose in the writer's practice. 
Applied on a pellet of cotton it acts as an anodyne, and the resin 
hardens in the cotton, forming with it a temporary stopping which will 
even bear the force of mastication for a few days. It is sometimes 
best to renew this dressing a few times before attempting a more per- 
manent treatment or filling. 

If the child cannot be brought to the office again within a few days, 
let the parent provide himself with a bottle of the carbolized resin and 
an inexpensive pair of dressing pliers. Instruct the patient how to 
apply the cotton dressing. This is the best domestic remedy for odon- 
talgia. Other medicaments may be used by the parent, such as oil of 
cloves, campho-phenique, etc., but their effect is much more temporary. 
A more durable dressing may be made by mixing zinc oxid and car- 
bolized resin to the consistence of putty and applying it in the cavity 
previously dried. It hardens under moisture, and makes a stopping 
that will remain, in some cases, for several weeks. 

During such palliative treatment, sometimes unavoidably extended 
over several weeks or even months, the child is growing older, is gain- 
ing experience, is becoming used to manipulation, begins to recognize 
the benefit of treatment of the teeth — in a word, is being trained or 
educated for a good patient for whom more permanent operations may 
be attempted. 

Prof. L. L. Dunbar says : " As a domestic palliative always at 
hand, in the treatment of pulp exposure and restricting odontalgia, use 
ammonia on cotton : its repeated use will devitalize the pulp, at the 
same time effecting its removal by saponification." 
1 Carbolic acid, 
Resin (colophony), da. ^j ; 

Chloroform, 15SS. 



668 MANAGEMENT OF THE DECIDUOUS TEETH. 

Treatment with Silver Nitrate. 

More than forty years ago the application of silver nitrate for 
arresting decay was advocated, but for many years no notice was taken 
of it. Within the last five years it has been advocated again, especially 
for use in the temporary teeth. The fact that it blackens the decayed 
surface is not as objectionable as with permanent teeth. Dr. Stebbins 1 
advocated the use of a solution of the crystals of silver nitrate in cari- 
ous cavities in temporary teeth. He applies it by means of a small 
stick inserted in a socket instrument as shown in Fig. 594. Many 

Fig. 594. 



cases will need no further treatment, decay being completely arrested. 
Some cases will need secondary treatment after a few months. In 
many cases he advises filling the cavity with gutta-percha after the 
application. 

Dr. C. N. Peirce 2 advises saturating pieces of blotting paper with 
40 per cent, solution of silver nitrate, and keeping these on hand for 
use. 

Dr. E. C. Kirk advises the use of asbestos felt for saturation with 
the solution in preference to blotting paper or cotton. He says : 3 " The 
contact of silver nitrate with vegetable fiber of any sort involves not 
only a destruction of the fiber but also of the silver nitrate, so that the 
preparation in a short time loses its desirable qualities." He advises 
that the asbestos felt be heated before the blowpipe before saturation, 
to burn out any organic material which may be present. 

Dr. A. M. Holmes 4 advises its use as follows for approximal cavities : 
" Cut away the walls to a V shape, and with a piece of gutta-percha, 
softened by heat, of the proper size to fill the space, bring the surface 
to come in contact with the diseased part of the teeth, into contact with 
the powdered crystals of silver nitrate and carry it to the place in the 
tooth or teeth prepared for its reception, packing it firmly and leav- 
ing it there to be worn away by use in mastication. When that takes 
place, the surfaces of the teeth treated will be found black and hard, 
with no sensitiveness to the touch or to change of temperature, and 
they will remain so indefinitely. In case the child is so timid as to 

1 International Dental Journal, 1891, p. 661. 2 Ibid., 1893, p. 152. 

3 Dental Cosmos, 1893, p. 667. * Ibid., 1892, p. 982. 



FILLING MATERIALS. 669 

prevent this course, dry the cavity, take out as much softened dentin 
as the patient will permit, carry the crystals on softened gutta-percha 
into the cavity and pack it, leaving it until such time as desirable to 
make a more thorough operation." 

In the writer's opinion it is better to open approximal cavities from 
the occlusal surface rather than make V-shaped spaces, as the full 
diameter of the teeth should be left to preserve the fulness of the 
arch. 

Silver nitrate in its action penetrates but a short distance. 

The Character of the Patient. 

The conditions of operating on the deciduous teeth vary so much 
from those pertaining to the permanent teeth that a different consid- 
eration must be taken of filling materials. 

The little patients' mouths are small. They are often too young to 
reason with or to understand the purpose of the operation. They have 
been too often frightened by thoughtless remarks of their elders in 
speaking of their dentist. 

Oftentimes the first sitting must be utilized merely to make the 
acquaintance of the child, perhaps cleaning the teeth a little, or intro- 
ducing some palliative dressing in an aching tooth. The greatest care 
should be taken not to hurt the child. After it has gained a little 
experience it recognizes the benefit of the treatment, and will often 
submit to operations that older patients even shrink from. 

Filling Materials. 

G-utta-percha. — Pink base-plate gutta-percha is a most valuable 
filling material. In approximal cavities where it is not exposed to 
wear and where the shape of the cavity is such as to retain it, it is 
practically indestructible. In occlusal and compound cavities in which 
it is exposed to wear it has wonderful durability, lasting in some cases 
for several years. 

Directions for Use. — Cut the gutta-percha in small pieces and place 
them on a gutta-percha warmer (see Fig. 304), where they can be kept 
soft but not heated enough to injure the material. The instruments 
also should be warmed (see Fig. 293). 

Occlusal Cavities. — Cut away the margins of thin enamel with 
suitably shaped chisels, and remove the decayed and softened dentin 
with scoop and hatchet excavators. Do this as thoroughly as the 
patient will permit, but do not sacrifice the patient to thoroughness, for 
the thorough removal of softened dentin is not as essential as with per- 
manent teeth, because the gutta-percha is, by mastication, kept in such 



670 MANAGEMENT OF THE DECIDUOUS TEETH. 

accurate contact with all the walls of the cavity that further soften- 
ing will go on very slowly if at all. No special attention need be paid 
to the form of the cavity, except that its mouth should not be larger 
than the rest, nor should any parts of the cavity be inaccessible to the 
filling material. After excavating, dry the cavity with bibulous paper, 
and apply campho-phenique, oil of cloves, or carbolic acid, to sterilize 
any softened dentin which may not have been removed. For drying 
cavities, prepare paper cylinders, of different sizes, as follows : Tear 
the bibulous paper in strips from half an inch to two inches in width. 
Roll or twist each of these strips into a rope, but not too tightly — just 
enough to retain the shape. Cut these ropes into cylinders from a 
quarter to half an inch in length. Some of these will be as large 
around as a lead pencil and others no larger than the lead itself. 

Protect the tooth from moisture as well as possible. For lower 
cavities fold a small napkin diagonally from the corner till it is about 
half an inch wide. Put the end of this between the gum of the upper 
canine and the lip and extend the napkin back between the upper 
molars and the cheek beyond the last tooth, then down behind the last 
lower molar, and press it between the lower teeth and tongue. Tell 
the patient to raise the tongue as it is applied, then to lower the tongue 
and hold the napkin with it. The part of the napkin between the 
upper teeth and the cheek will cover the mouth of the duct of 
Steno, and prevent or absorb the flow of saliva. It is better to cover 
the mouth of this duct with a piece of spunk about half an inch in 
diameter before applying the napkin. The folds of napkin between 
the lower teeth and tongue and under the tongue will absorb the saliva 
from the submaxillary glands. This part of the napkin can be held in 
place with a mouth mirror or other blunt instrument, by the operator 
or assistant. After applying the napkin use a large bibulous paper 
Cylinder to absorb the moisture from the tooth to be filled and also 
from contiguous ones. With smaller cylinders or pellets dry the cavity. 
Apply once more campho-phenique or other medicament, and absorb 
the excess. 

The gutta-percha having been meanwhile warmed and softened, 
pick up a small piece of it with a cold round-pointed instrument 
and press it into the cavity. If the cavity is not large, a single 
piece of gutta-percha of a diameter less than that of the cavity, but 
longer than the cavity is deep, can be pressed in quickly and at one 
movement. For medium-sized cavities select a piece of gutta-percha 
large enough to cover the floor of the cavity and press it into place 
with a cold instrument, as a warm instrument might drag it from its 
place. Add similar pieces, pressing each one to the place in which it is 
till the cavity is full. If at any time the gutta-percha in the 



FILLING MATERIALS. 671 

cavity becomes so hard as to lose its plasticity, apply a warm instrument 
to soften the surface, so that the next piece will adhere to the others. 
As the filling nears completion select a small piece for the last, just 
large enough to complete the filling and no more, so that none will 
have to be trimmed away, for in trimming the surplus away the filling 
may be drawn from contact with the walls of the cavity. 

In filling large cavities it may be necessary to hold the first piece in 
position with another instrument till sufficient material is added for self- 
retention. At the completion of the filling slight pressure with a warm 
instrument should be made in such a manner as to force the material 
against all the margins of the cavity. 

Approximal Cavities. — Where possible, approximal cavities 
should be opened from the buccal surfaces, as advised by Dr. Bon- 
will, as in such cases gutta-percha fillings will not be exposed to the 
force of mastication. This plan is not often practicable because the 
patient is seldom presented till the cavity has become visible by open- 
ing into the occlusal surface of the tooth. In such cases cut away the 
enamel only enough to give access to the cavity, excavate the decayed 
dentin, and trim the buccal, lingual, and cervical walls until a smooth, 
firm margin is obtained. 

In filling such a cavity use small pieces of softened gutta-percha,, 
pressing each piece where it is to remain, and avoid a surplus. Press 
the gutta-percha against the adjoining tooth as if it were a matrix or a. 
fourth wall of the cavity and let it remain. It is useless to trim it 
away from the adjoining tooth, because the force of mastication would 
soon spread the filling against it again. 

If an approximal cavity cannot be readily shaped so that it will 
retain the gutta-percha, it may be packed against the adjoining tooth, 
as if it were an occlusal cavity. It will prevent decay, especially if sil- 
ver nitrate is applied as described on page G68, and maybe retained till 
the patient is older, when a more thorough operation may be performed. 

The spreading of the gutta-percha by the force of mastication will 
tend to separate the teeth — which is sometimes an advantage ; and also 
to press upon the gum in the interproximal space — which is a disad- 
vantage. In filling children's teeth we cannot always reach the ideal, 
but must select the method and material which will have the greatest 
advantage with the least disadvantage. If the teeth separate so much 
that the pressure of the gutta-percha upon the gum tissue becomes a 
serious annoyance, some other material must be substituted. Zinc 
phosphate cement is probably the best. 

To prevent the impinging of the gutta-percha upon the gum in the 
interproximal space, Dr. M. W. Hollingsworth l has invented a space 
1 Dental Cosmos, 1896, vol. xxxviii. p. 553. 



672 



MANAGEMENT OF THE DECIDUOUS TEETH. 



guard, consisting of a concave elliptical piece of metal coated on the 
convex surface with gutta-percha. This guard is to bridge over the 
interproximal space. It is placed in position with the instrument 
shown in B, Fig. 595, which is warmed slightly, so that the point can 



Fig. 595. 



Fig. 596. 





enter a small hole in the guard and adhere to the gutta-percha on the 
under side, as shown at c. The guard is placed in the cavities, after 
warming the gutta-percha, as shown in Fig. 596, and thus covers the 
cervical borders. Gutta-percha is now filled in over the guard as if 
the two cavities formed a single crown cavity. 

Advantages of Gutta-percha. — It is easily applied to the cavity ; it is 
insoluble ; is durable even when masticated upon ; is a non-conductor of 
thermal impulses ; the filling is finished as soon as the cavity is full ; it 
spreads under the force of mastication, and is thus kept in contact with 
the walls of a cavity ; it can be used even under moisture. 

Disadvantages. — Gutta-percha is softer than other filling materials, 
and hence wears away more rapidly. In approximal cavities it will 
spread the teeth apart, and may then press upon and irritate the gum. 

Dryness of the cavity, though very desirable, is not absolutely neces- 
sary. 

Advantages of Zinc Phosphate Cement. — It is a poor conductor of 
heat ; it withstands the force of mastication better than gutta-percha ; 
it adheres to the walls of the cavity, and hence will remain where no 
other material can ; it is easily applied ; its color may be selected to 
match the tooth. 

Disadvantages. — Absolute dryness of the cavity is a prerequisite to 
its success ; it must be kept dry for several minutes after it is inserted 
in the cavity. Zinc phosphate cement disintegrates in some mouths 
much more rapidly than in others. If placed too near the pulp it may 
by chemical irritation devitalize it. 



FILLING MATERIALS. 673 

Application of the Rubber Dam. — While many hesitate to attempt 
the use of the rubber dam with children, it will be found upon trial that 
most of them will submit to it without trouble, and many will prefer it 
to other means of keeping cavities dry. 

Although there is an advantage in applying the rubber dam before 
excavating — because dryness makes the teeth less sensitive, and a clearer 
view of the cavity is obtained — still, for the sake of not tiring the little 
patients by too long restraint in one position, it is better to do most of 
the excavating before its application. 

The small size of the necks of the deciduous teeth compared with 
that of the crowns renders the retention of the rubber dam easier than 
with permanent teeth. Even considering the smallness of the patients' 
mouths, the application of the rubber dam is not difficult in many 
cases. 

For retaining the rubber dam on the second molar a clamp will 
sometimes be necessary, but for the other deciduous teeth a floss silk 
ligature will be sufficient. Having punched holes of suitable size 
through the rubber dam, apply it over the teeth affected. If the cavity 
is in the occlusal or buccal surface only, it will not be necessary to 
apply it over more than one tooth, but if the cavity is in the approximal 
surface it will be necessary to apply the rubber dam over two or some- 
times three teeth, or even more, if several cavities are to be filled at one 
sitting. 

It is not always necessary to tie a ligature around the neck of the 
tooth, as merely passing the Avaxed floss silk between the teeth will 
often force the rubber around the neck of the tooth enough to retain it 
even above an approximal cavity. The silk may then be removed by 
drawing the end through between the teeth. 

With a thin burnisher or spatula turn up the edge of the rubber 
around the neck of the tooth toward the gum. The tendency of the 
rubber then will be to slide in that direction and not off over the 
crown. If a ligature be necessary to hold the rubber above the edge of 
an approximal cavity tie it tightly around the neck of the tooth, even 
forcing it toward or under the edge of the gum with an instrument when 
necessary. The clamp on a second molar may often be dispensed with 
after a ligature is applied, unless it is needed to hold the rubber out of 
the operator's way. The only object in omitting the clamp is to pre- 
vent pain or discomfort to the child. 

If a simple ligature will not retain the rubber on a second molar 
before the first permanent molar has appeared, its efficiency may be 
greatly increased by stringing a bead, about an eighth of an inch or less 
in diameter, on the thread and tying a simple knot in it so that the bead 
will be in about the middle of the ligature. Tie the ligature around 

43 



674 MANAGEMENT OF THE DECIDUOUS TEETH. 

the tooth so that the bead will lie against the distal surface of the 
second molar on or near the gum. This bead will prevent the rubber 
slipping off the tooth. A short cylinder of bibulous paper can be tied 
in the ligature and applied with the same effect, and even a large knot 
in the ligature on the distal surface of the tooth will often answer the 
purpose. 

The corners of the rubber dam should be held out of the way by a 
suitable holder extending around the head. The lower border may be 
held out of the operator's way by small weights, hooked in the edge. 

Dry the cavity and the whole tooth or teeth, and complete the 
excavation. 

Pilling- Cavities with Cement. — As cement can be applied easily 
in undercuts and very irregularly shaped cavities it is not necessary to 
cut away the enamel more than is sufficient to enable the operator to 
thoroughly remove the disintegrated dentin. Even the thorough re- 
moval of the latter is not as essential for a cement filling as for other 
materials, for, if the edge of the cavity can be made smooth and the 
softened dentin be thoroughly sterilized, the cement will hermetically 
seal it and prevent further disintegration until it is worn away beyond 
the sound edges. 

The operator may take much greater risks in leaving disintegrated 
dentin than with permanent teeth, for the object is simply to retain the 
tooth till the time arrives for its successor to appear. 

It must be remembered in excavating cavities in deciduous teeth 
that the pulp is much larger in proportion to the size of the crown than 
in permanent teeth, and that in trying to make undercuts or retaining 
grooves deep enough to retain a filling, the pulp may be exposed — an 
accident which should be carefully guarded against, for the pulp has 
not even the recuperative power possessed by the pulp of a permanent 
tooth, and in case of its death it is more difficult to give a deciduous 
tooth proper treatment. Moreover, death of the pulp prevents normal 
resorption of the root and may thus cause irregularity of the permanent 
teeth. 

For most cases the cement should be mixed as thick as can be easily 
and quickly manipulated, but if the pulp is nearly exposed the cement 
should be used so thin that it can be applied without pressure, by 
flowing it over the floor of the cavity. Cement mixed moderately 
thin will adhere better to the walls of the cavity than when it is as 
thick as it is possible to apply it. The thinner the cement, the longer 
time it will take to harden, but the thicker it is mixed the more dur- 
able it will be. Do not keep the little patient in a constrained posi- 
tion longer than necessary. The easier the first operation is for him 
the more readily will he return for the second. 



FILLING MATERIALS. 675 

If the pulp is very nearly exposed apply Fletcher's carbolized resin 
over the floor of the cavity. For this purpose remove the stopper of 
the bottle till by evaporation the carbolized resin has thickened to the 
consistence of molasses. Dip a small probe in this thickened mass, so 
that a small drop will adhere to the end. This drop may be then con- 
veyed to and spread over the floor of the cavity. This will prevent 
contact of the cement with the most sensitive dentin and lessen the 
possibility of deleterious action on the pulp. 

Where it is possible to apply the rubber dam and excavate thoroughly 
the same excellent result with cement may be expected as when it is 
used in permanent teeth, but often it is not possible to operate as 
thoroughly. 

By applying melted paraffin 1 or sandarac varnish to the cement the 
rubber dam may be removed sooner than otherwise, and the cement 
will be protected from moisture by the coating of paraffin or varnish. 

As paraffin is insoluble in any agent that can attack it in the mouth, 
the more it is absorbed by the cement the longer it will protect it from 
everything but wear ; therefore, do not be content to merely flow the 
melted paraffin over the cement, but hold a heated instrument in contact 
with the filling and keep the paraffin melted until all that is possible is 
absorbed. If an approximal filling has been inserted pass a very thin 
heated spatula between the cement filling and the adjoining tooth to 
make sure that the paraffin covers it to its cervical margin. 

When the rubber dam cannot be applied, cement may still be used 
with success if the cavity can be kept dry with napkins or rolls of 
cotton or spunk until it is inserted and quickly covered with melted 
paraffin. 

Deep cavities may be advantageously lined with cement and protected 
with paraffin till the cement is hard, Avhen the paraffin may be removed 
and gutta-percha or amalgam inserted. 

Cavities in Incisors. — Decay in deciduous incisors is much more 
rare than in the other teeth, and they are lost so early in child life that 
it is seldom necessary to fill them. Zinc phosphate cement is the best 
filling material for these teeth, because they are so small that it is very 
difficult to shape the cavities properly for retaining other materials. 

If it is found that cement disintegrates rapidly in approximal cavities, 
an attempt should be made to shape them so as to retain gutta-percha. 
The first filling of cement may have removed the sensitiveness suf- 
ficiently to allow deeper excavating at a subsequent sitting, or there 
may have been a deposit of secondary dentin, thus removing the pulp 
from danger of exposure in properly shaping the cavity. 

Amalgam. — While amalgam is a valuable filling material, its use 
1 Dr. Bonwill's suggestion. 



676 MANAGEMENT OF THE DECIDUOUS TEETH. 

necessitates much greater care in the preparation of cavities than is 
necessary with gutta-percha or cement, for it neither spreads under 
mastication like the former nor does it adhere to the walls of a cavity 
like the latter. The spreading of gutta-percha will stop a leak that 
would be fatal to an amalgam filling, and cement will adhere in a cav- 
ity from which amalgam would be easily dislodged. 

Amalgam should be used when the decay can be thoroughly excava- 
ted and the cavity prepared with strong smooth edges, and good under- 
cuts or retaining grooves. As amalgam is a better conductor of thermal 
impulses than either of the materials before mentioned it will not be 
tolerated so near the pulp, hence deep cavities must be lined with either 
gutta-percha or zinc phosphate. 

The large size of the pulp of deciduous teeth — greater in proportion 
than that of the permanent teeth — must not be forgotten in exca- 
vating, and often it is impossible to make suitable retaining grooves for 
amalgam without cutting dangerously near the pulp, especially in ap- 
proximal cavities. 

The preparation of occlusal cavities is comparatively simple, as the 
enamel may be easily cut away so as to make firm edges, slightly 
bevelled, and to allow thorough excavation of softened dentin. 

The burring engine can be used to greater advantage Avith children 
than many would suppose. The whirring noise often distracts their 
attention from a slight pain they might otherwise notice, and the assur- 
ance that the work can be done more quickly is a great encouragement. 
In preparing approximal cavities for amalgam a free opening should 
be made in the occlusal surface and given a dovetail shape, extending 
farther upon the occlusal surface in proportion to the size of the cavity 
than in permanent teeth, because more reliance must be placed on it for 
retention than upon lateral grooves, for there is not much depth of 
dentin in which to make them. The cervical border of the cavity must 
be smooth and the floor at right angles to the long axis of the tooth. 
The lateral walls must be cut smooth and bevelled, and may be 
slightly grooved. If the cavity extends below the 
margin of the gum the latter should be crowded 
away with a temporary stopping or by packing a 
tightly rolled pledget of cotton between the teeth 
and relying on its swelling. 

While the application of a rubber dam is not as 
Prepared cavity showing essential as in using cement, it is a great advantage,. 

bevelling of enamel . ft 7 . ° ° 7 

edges, a,a, and square for it renders the proper preparation of the cavity 
base for filling, b. more cer t a in, but it need not be applied till the 

cavity is nearly prepared. Its use is more often necessary with the 

lower teeth than with the upper. 







EXPOSED PULPS. 677 

Amalgam should not be mixed too dry, but should be plastic enough 
to be packed easily without crumbling. In occlusal cavities introduce a 
piece half as large as the cavity, and with a small ball burnisher spread 
it over the floor of the cavity toward the walls. Introduce other smaller 
pieces and proceed as before until the cavity is nearly full. Excess of 
mercurv is thus forced to the edges of the cavity, whence it can be 
brushed away with cotton or bibulous paper. 

The last pieces of amalgam should be " wafered," as recommended 
bv Prof. J. Foster Flagg — that is, squeezed in chamois skin with large 
flat-nosed pliers till as much mercury as possible is pressed out (see 
Fig. 288). This leaves the amalgam in a thin, brittle wafer, too hard 
for ordinary use. Break it up in pieces half the diameter of the cavity. 
Press one of these in the middle of the nearly completed filling. It 
will readily absorb the excess of mercury that has been worked to the 
surface, and can be spread toward the margins with a round burnisher. 
Other pieces can be burnished on till the filling is quite hard. 

In filling approximal cavities the same plan may be followed if a 
matrix of thin steel or German silver be used. In lieu of the matrix 
a very thin spatula may be held between the teeth. 

Whenever possible, fillings in deciduous molars should be contoured 
to avoid the crowding of food between the teeth and also to prevent the 
first permanent molar from crowding them together and thus taking up 
room which will be needed by the bicuspids. 

The child should be cautioned against masticating too soon upon 
approximal fillings, though no caution is needed in case of occlusal fill- 
ings hardened by the " wafering " process. 

Tin and gold are excluded from the list of desirable filling materials 
for temporary teeth, not because they are not good filling materials but 
because the circumstances are such that they cannot be used to advan- 
tage. Though a small gold filling may be inserted in a few minutes in 
an occlusal cavity, the insertion of a large gold filling would be inflict- 
ing a needless cruelty on a child on account of the length of time it 
must be held in one position. 

As the insertion of a tin filling is nearly if not quite as difficult and 
tedious an operation, it is open to the same objection. 

Exposed Pulps. 

On account of the difficulty of properly capping an exposed pulp in 
a deciduous tooth, the operation should seldom be attempted. It is 
better to devitalize the pulp and remove it. 

The writer has found the following formula l an excellent one : 

1 Used bv Dr. E. N. Clarke in the "fifties." 



678 MANAGEMENT OF THE DECIDUOUS TEETH. 

^. Acidi arseniosi, 
Morphia? acetatis, 
Pulv. opii, da. pars wq. 

Creosoti q. s. to make paste. 

Why opium and acetate of morphia should both be used in the same 
prescription is not clear, as their properties are so nearly the same, but 
the paste has been satisfactory in devitalizing pulps with no pain, or 
with a minimum amount. Other formulas may be equally satisfactory. 

In occlusal cavities its application is simple. Excavate the softened 
dentin as thoroughly as possible without inflicting pain, using spoon- 
shaped excavators to prevent puncturing the pulp. If the excavation 
can be carried far enough to apply the paste directly to the pulp its 
action will be more rapid. Dry the cavity, apply a small amount, not 
larger than half a pinhead in size, with a small probe and cover it with 
a pellet of cotton, or place in the cavity a small pellet of cotton one 
side of which has been touched to the paste. Add enough pellets of 
dry cotton to fill the cavity, then apply a drop of sandarac varnish, suf- 
ficient to saturate at least half the depth of cotton. This is a better 
plan than dipping the pellets in the varnish before inserting, because an 
excess of the latter is apt to come in contact with the pulp and cause 
pain, or, penetrating between the paste and the pulp, may render the 
former inoperative. Temporary stoppings such as Gilbert's, White's, or 
Fowler's are excellent for sealing the cavity, but take a little more 
time than cotton and varnish. Such temporary stopping should be well 
softened by heat to prevent pressure on the pulp in its insertion. A 
good plan is to warm the end of the long stick of stopping and press 
it into the cavity, using the remainder of the stick as a handle, then 
remove the surplus and smooth with a warm instrument. 

In approximal cavities extending near or under the margin, the gum 
should be protected, before applying the paste, as follows : 

Make, by rolling between the fingers, a cylinder of cotton as long 
as the width of the tooth and about the size of the lead of a pencil. 
Saturate it with sandarac varnish and pack it between the teeth upon 
the gum, extending part of it below the edge of the cavity, thus sealing 
this portion of the cavity and reducing it nearly to the form of an 
occlusal cavity. Paste applied in an approximal cavity so protected 
cannot flow upon the gum unless too great a quantity has been used. 
The paste should be applied and sealed as in an occlusal cavity. 

" Devitalizing fiber" is very satisfactory and may be used with less 
fear of its affecting the gum tissue. 

The paste may be allowed to remain in the cavity for from twelve 
to forty-eight hours. The possibility of the dressing being dislodged, so 



FILLING PULP CANALS. 679 

as to allow the paste to come in contact with the gum tissue, should 
warn one to have the patient return much sooner than when the case 
is an occlusal cavity from which it is impossible for the paste to escape. 

Much has been said about the danger of application of arsenic in 
deciduous teeth when the roots are undergoing resorption, but the 
writer has never seen any bad effects from such use ; still it must be 
admitted that the ratio of danger varies with the degree of resorption 
of the root. An examination of Prof. Peirce's diagram (Fig. 593) will 
show the average amount of resorption at different ages, and enable 
one to discriminate. The writer believes that the sensitiveness of a 
deciduous pulp varies inversely with the amount of resorption of the 
root, and that devitalization is called for in very few cases in which 
there is clanger of deleterious action. 

Prof. L. L. Dunbar advises the use of aqua ammonia? for devitaliz- 
ing the pulp of a temporary tooth, by applying it on a pledget of cotton 
in the cavity, one or two applications being sufficient in most cases. 
This plan is not open to the objections urged against the use of arsenous 
oxid. 

When the pulp is devitalized, open the cavity freely into the pulp 
chamber and apply on cotton a solution of tannic acid in glycerol. 
Leave this about a week, by which time the pulp tissue will have be- 
come so hardened by the tannin that it may be removed much more 
readily than without such treatment. 

The application of mummifying paste is advised by many, after 
devitalization, to avoid the necessity of removing the pulp. If a real 
mummifying paste can be found, its application will be the ideal 
treatment. 

Filling Pulp Canals. 

In the pulp canals apply iodoform paste made by mixing iodoform 
and glycerol to such a consistence that it can be readily applied on a 
probe. 

Fill the pulp chamber with ''temporary stopping" or gutta-percha, 
and the cavity with cement, gutta-percha, or amalgam according to 
indications. 

If the tooth be very frail, fill the cavity with cement, because, owing 
to its adhesive properties, it strengthens the tooth. If the cavity be 
approximal and it is desirable to wedge the teeth apart, use pink gutta- 
percha. 

If the walls be strong and some time will elapse before the natural 
exfoliation of the tooth will occur, fill with amalgam. 

If absorption of the roots occurs, the iodoform in the canals will not 
interfere. 



680 MANAGEMENT OF THE DECIDUOUS TEETH. 

Salol, which was advocated as a root filling for permanent teeth by 
Dr. A. E. Mascort l of Paris, France, is well adapted also for filling the 
canals of deciduous teeth. "It is a white crystalline powder, insoluble 
in water and glycerol, but soluble in alcohol, ether, chloroform, etc. ; 
fuses at 40° C. but crystallizes quickly again." Melted together, salol 
and aristol, salol and iodoform, or salol and paraffin, become liquid 
like salol alone. After a pulp canal is thoroughly dried the salol may 
be fused on a small spatula and carried to the canal, into which it will 
be taken by capillary attraction or a broach may be heated and inserted 
in the salol. A small quantity will adhere like a drop of liquid and 
may thus be carried to the canal. The heated broach may be again 
introduced in the canal to insure thorough application. Dr. Mascort 
uses the hypodermic syringe with a small needle for introducing into 
the canals. It will crystallize in a very short time, making a solid fill- 
ing. Though the writer has not had much experience with salol as a 
root filling, he is so far well pleased with the result. (See Chapter 
XVII., p. 439.) 

Alveolar Abscess. 

The treatment should be the same as with the permanent teeth, that 
is, removal of the cause — which is, almost invariably, a decomposed 
pulp. Even with a decomposed pulp an abscess seldom occurs if there 
be any opening from the cavity of decay to the pulp chamber, unless 
such opening has become stopped by some foreign substance. 

Make a free opening into the pulp chamber and with a syringe 
wash out as much of the contents as possible. Dry the chamber and 
with a "minim " syringe (see Chapter XVII. , Fig. 441), or drop tube, 
.apply hydrogen dioxid. While capillary attraction will carry this 
into a dry canal, the application of a nerve broach, preferably platino- 
iridium, will serve to mix it thoroughly with the contents of other 
canals, and increase its efficiency. 

If a fistulous opening has formed through the outer alveolar plate 
but not through the gum, an opening should be made through the latter 
with a sharp lancet about five minutes after the application of 4 per 
cent, cocain hydrochlorid solution on a wad of cotton. 

If hydrogen dioxid can be forced from the pulp chamber through 
the root canals and fistulous opening, the accumulated pus will be 
thoroughly evacuated and the cure hastened. As a rule, however, the 
abscess disappears after the cause is removed, that is, the putrescent or 
decomposed contents of the pulp chamber and canals. 

After drying the pulp chamber and canals, apply iodoform paste 

1 Dental Cosmos, 1894, p. 352. 



PROPHYLACTIC TREATMENT. 681 

therein and seal the cavity for a few days with temporary stopping. 
"When the inflammation of the pericementum has disappeared the pulp 
chamber and canals may be filled as before directed. 

In many cases the inflammation of the pericementum will be so 
great, or in popular expression the tooth so " sore " to the touch, 
when the case is presented that at the first sitting nothing more can be 
done than to make an opening into the pulp chamber to allow the escape 
of pus or gases of decomposition. By this means the pain will be re- 
lieved and the rest of the manipulation and treatment may be left till 
the inflammation has subsided. 



Prophylactic Treatment. 

This lies more in the hands of the parent than of the practitioner, 
but should be strongly urged by the latter upon the former. The nurse 
or parent should begin early to clean the child's teeth by means of a 
cloth wrapped around the finger. If the teeth cannot be kept clean in 
this manner a small brush should be used, especially after eruption of 
the molars. Floss silk should be used daily between the teeth. One 
end of the silk should be held in each hand in such a manner as to pass 
over the end of each index finger and be made taut between them. 
This taut part can be pressed down between the teeth and passed up and 
down against the approximal surface of each tooth, then one end of the 
thread should be released from one hand and pulled through the 
interdental space with the other. 

This will drag out any particles of food that may be there, and is 
much better than the toothpick for the purpose. If particles of 
meat or other food have lodged so firmly that the plain waxed silk 
will not dislodge them, tie a single knot in the thread and pull that 
through. 

This cleansing with the cloth, brush, and silk should be done before 
the child retires at night, for that is the " period of decay." The parts 
are at rest longer than at any other time, and the fluids of the mouth 
are not kept in circulation between the teeth by means of the tongue, 
lips, and cheeks. Theoretically the teeth should be thus thoroughly 
cleaned after each meal, but " satiety breeds disgust," and it is not 
best to insist on more than will probably be accomplished. 

Children will soon learn to use the brush and floss silk themselves, 
and finding the mouth much more comfortable when " clean" they will 
endeavor to keep it so. Many a child has been denied candy for vears 
from the belief that " sweets decay the teeth," but parents may be as- 
sured that no harm will be done if the " sweet " is not allowed to 
remain between and around the teeth till it becomes acid, and that 



682 MANAGEMENT OF THE DECIDUOUS TEETH. 

may be prevented by cleansing the teeth after the candy or sugar is 
eaten. A child may be taught cleanliness in this manner who would 
be only taught rebellion by the repeated denial of sweets, the reason of 
which he cannot understand. 

Prophylactic mouth-washes should be used — such as listerine diluted 
to a 10 per cent, solution. 



CHAPTER XXIY. 

ORTHODONTIA EXCLUSIVELY AS AN OPERATIVE 
PROCEDURE. 

By Clark L. Goddard, A. M., D. D. S. 



The Normal Arch. — As the study of physiology is necessary before 
the study of pathology, so is a study of the normal arrangement of the 
teeth necessary before the treatment of their irregularities should be 
undertaken. 

The ideal facial profile is shown in Fig. 598. The face from the 

Fig. 598. 




The facial profile. 

hair to the chin measures three-fourths of the whole height of the head. 
The forehead to the root of the nose measures one-fourth, the nose one- 
fourth and the mouth and chin one-fourth. The distance vertically 
from the root of the nose to its lower border is equal to the distance 
from this point to the bottom of the chin. Of this latter distance one- 
half is occupied by the lips and one-half by the chin. The nose, then, 
equals in length the lips and chin. 

683 



684 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



The upper dental arch is shown in Fig. 599. The six anterior teeth 
are arranged in the segment of a circle. The bicuspids and molars 

Fig. 599. 




Normal upper dental arch. 

form almost straight diverging lines from the canines, though the posi- 
tion of the third molar is somewhat outside of that line. 

The normal occlusion of the teeth is shown in Fig. 600. The 
six upper anterior teeth close over the six lower from a third to a half 

Fig. 600. 




\ ■- 




Normal occlusion. 



of the length of the latter. The lower second bicuspid occludes between 
the cusps of the two upper bicuspids and is the hey to the occlusion; 
this is a point easily remembered. Each bicuspid and molar of each 
jaw, excepting the upper third molar, is antagonized by two of the 



DISTAL OCCLUSION. 



685 



teeth of the opposite jaw. The buccal cusps of the lower teeth close 
between the buccal and lingual of the upper, and the lingual cusps of 
the upper close between the lingual and buccal cusps of the lower. 

As the lower jaw moves laterally during mastication the cusps of the 
bicuspids and molars grind upon each other, while the six anterior teeth, 
overlapping but not touching, pass by each other and escape wear. In 
order to touch the cutting edges of the upper and lower incisors upon 
each other the lower jaw is protruded, and at such a time the masticat- 
ing teeth do not occlude. 

Mal-occlusion may be of many kinds and degrees, to which no 
general description can be given. The eruption of a single tooth 
labially or lingually or turned on its axis may disarrange the occlusion 
of all the neighboring teeth or even all the teeth of both arches. Like- 
wise the loss of a single permanent tooth or its failure to erupt may 
have a more disastrous effect. 

There are many cases, however, in which both arches are normal, 
yet their relation to each other is such that it results in mal-occlusion. 

The nature of such mal-occlusion of the arches as a whole may be 
indicated by the position of the second lower bicuspid, which is the 

Fig. 601. 




Distal occlusion of the jaws. 



key to the occlusion ; according to its position, the occlusion of the 
arches may be described as normal, distal, mesial, lingual, or buccal. 

If the key tooth, the second lower bicuspid, closes between the 
upper bicuspids, with its buccal cusp between their buccal and lingual 
cusps, the occlusion, both of the key tooth and all the others, is normal 
(Fig. 600). 

Distal Occlusion. — If the key tooth closes posteriorly or back of 
the normal position to any degree, even to the width of a bicuspid or 
more, the occlusion is distal, as shown in Figs. 601 and 603. This 
mal-occlusion may be on one or both sides of the mouth. It may be 
due to lack of development of the lower maxilla, or the fault may be 
in the temporo-maxillary articulation. 



686 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



An upper protrusion may be described as a distal occlusion of the 
lower jaw on both sides (or a bilateral distal occlusion). 

Mesial Occlusion. — If the key tooth closes anteriorly or mesially 
to the normal position to any degree, even to the width of a bicuspid 
or more, the occlusion of the jaws is shown to be mesial (Fig. 602). 
This may occur on one or both sides of the mouth and may be the fault 
of the teeth themselves, if the abnormality is slight. It may be due 
to lack of development of the upper maxilla, as in Fig. 779 ; or abnor- 
mal development of the lower maxilla, as shown in Fig. 780, both 

Fig. 602. 




Mesial occlusion of the jaws (also buccal occlusion and mesio-buccal occlusion). 

being cases of lower protrusion. Hence lower protrusion may be de- 
scribed as mesial occlusion of the lower jaw (or lower maxilla). 

Buccal Occlusion. — If the lower arch is wider than the upper, so 
that the buccal cusps of the lower bicuspids and molars do not close 
between the buccal and lingual cusps of the upper teeth, but close 
outside in any degree, even to the width of a cusp or more, the key 
will be found in a buccal position, and the whole occlusion is buccal, 
as shown in Figs. 602 and 781. 

This may occur on one or both sides of the arch (unilateral or 
bilateral), and may be due to a narrow upper arch or a wide lower 
arch. 

Lingual Occlusion. — If the lower arch is so narrow that the buc- 
cal and lingual cusps of the lower bicuspids do not close between the 
buccal and lingual cusps of the upper teeth, but close inside or 
toward the median line of the mouth to any degree, the key tooth 
will be found in a lingual position and the whole occlusion is lingual 
(Fig. 807). 

This may be due to a slight disarrangement of the teeth themselves, 
or to abnormal development of the upper or lack of development of 
the loAver maxilla. 

Lingual occlusion may occur on one or both sides of the arch (uni- 
lateral or bilateral), or-there may be lingual occlusion on one side and 
buccal occlusion on the other. 



LABIAL ASPECT. 



687 



In cases of bilateral mal-occlusion either buccal or lingual expansion 
of the lower or upper arch is indicated. 

Two of these positions may occur at once while the single arches 
themselves are comparatively normal. 

A disto-lingual occlusion is shown in Figs. 603 and 807. 

A mesio-buccal occlusion is shown in Figs. 602, 780, and 781. 



Fig. 603. 




Fig. 604. 




Disto-lingual occlusion of the jaws. 

Labial Aspect. — In examining the upper six anterior teeth from 
the labial aspect (Fig. 604) it will be seen that they touch each other 
at one point only, about one-fourth 
of the distance from the cutting edge 
to the gum ; also that the long axes 
of the teeth are not parallel, but the 
crowns slant toward the median line. 
Of the six upper anterior teeth the 
central incisors are the longest, the 
laterals next, and the canines short- 
est, though popularly the canine is 
thought to be the longest tooth be- 
cause of its prominence and the length of its cusps. It will be 
noticed that the gum line is higher on the canine, thus adding to its 
apparent length. 

A line connecting the cutting edges and cusps of half the upper 
teeth forms a double curve, highest at the third molar and lowest at the 
central incisor, the line of beauty, while such a line on the lower teeth 
forms but one curve, highest at its ends. 

While the aim of the student of orthodontia will be to correct all 
irregularities and reduce the abnormal to the normal, it will be possible 
in many cases to do this only in degree. The normal may always be 
approached, but not always attained. 



The six anterior upper teeth. 



688 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

Order of Eruption of Permanent Teeth} 
1. Central Incisors — from 6th to 8th year. 



2. 


Lateral " 


u 


7th" 


9th " 


3. 


Lower Canines 


a 


8th " 


10th " 


4. 


First Bicuspids 


a 


9th " 


10th " 


5. 


Second " 


a 


10th " 


12th " 


6. 


Upper Canines 


u 


11th " 


12th " 


7. 


First Molars 


a 


5th " 


6th " 


8. 


Second " 


a 


12th « 


14th " 


9. 


Third " 


u 


17th " 


25th " 



While most tables place the eruption of all the canines after that 
of the bicuspids, it will be noticed that in this the lower canine pre- 
cedes and the upper canine follows both bicuspids. 

The lateral incisor fails to erupt more often than any tooth except 
the third molar. It also erupts out of line more often than any tooth 
except the canine. 

Fig. 605. 




Upper and lower casts showing in the same mouth the two irregularities mentioned on page 689! 

The lateral incisor is duplicated more often than any other tooth, 
cases of five or six incisors sometimes arranged in the normal curve 
1 Farrar, Treatment of Irregularities of the Teeth, vol. i. p. 483. 



THE DECIDUOUS TEETH. 



689 



of the arch, but more often crowded out of line, being seen occasionally. 
This is evidently a reversion to the six incisors of the normal mam- 
malian formula : 



3_3 i_i 4_4 3_3 

J 3^3 C lH Pm 4=4 M 3=3 



44. 



Occasionally a bicuspid (premolar) is duplicated, a reversion to the 
before-mentioned type, in which four premolars are normal. 

The difference in the order of eruption of the upper and lower canines 
has an effect upon the position of those teeth. The upper canine erupts 
out of line more often than the lower, while irregularity of the lower 
bicuspids is more frequent than of the upper. In each case, being the 
last of the successional teeth to erupt, there is often insufficient room to 
enable them to assume their normal positions. (See Fig. 605.) 

The Deciduous Teeth. 

The position of the deciduous teeth is almost always normal. One 
or two teeth may be misplaced, either by an inherited tendency or by 

Fig. 606. 




Upper and lower jaws of a child aged about six and a half years, showing portions of the 
developing permanent teeth and the roots of the deciduous teeth. 



pernicious habits, such as sucking the thumb. The irregularity, how- 
ever, is so slight and so infrequent, and the deciduous teeth are retained 
in the mouth for so short a time, that there is no occasion for treatment. 
A regular arch of the deciduous teeth does not, however, foretell a 
regular arch of the permanent teeth. Fig. 606 will make evident that 
the crowns of the permanent incisors, canines, and bicuspids are formed 

44 



690 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

in the jaw before the roots of the deciduous teeth are absorbed. From 
want of space they are crowded together, and already present all phases 
of irregularity. 

The late Prof. J. H. M'Mullen said of such cases : " When we are 
examining a series of jaws of different ages, arranged so as to show 
deciduous and permanent teeth, it is not a surprising matter that there 
should be irregularity in the permanent set ; but when observing their 
crowded and irregular arrangement in the jaw prior to eruption, it is 
rather a matter of astonishment that they should ever assume a regular 
symmetrical appearance." 

As the permanent teeth are larger than the deciduous, the question 
naturally arises, How is room provided for them ? 

This may be answered, first, by dividing the permanent teeth into 
two classes : those which replace the deciduous teeth and those which 
do not. For the first class — that is, the incisors, canines, and bicuspids — 
room is made by interstitial growth and by the fact that the biscuspids 
are smaller than the deciduous molars which they replace. For the 
permanent molars room is made by growth of the posterior portion of 
the jaw. 

Etiology of Dental Irregularities. 

The causes of irregularities of the teeth may be divided into three 
classes — hereditary, constitutional, and acquired. 

As children inherit other peculiarities of structure from father, 
mother, grandparent, or even from more remote ancestors, so may irreg- 
ularities of the teeth be inherited. The causes are operative before the 
birth of the child. 

Hereditary causes may be divided into two : (a) Direct, in which a 
child inherits some distinct irregularity just as he may inherit some 
other distinctive feature. (6) Indirect, in which he inherits separate 
peculiarities which combined will cause an irregularity. For example, 
large teeth may be inherited from one parent and small jaws from the 
other, and thus will be produced an irregularity of some kind, but not 
inherited directly from either. A child may inherit tone of voice, 
peculiar gait, or other habit ; so he may inherit a habit which will cause 
an irregularity. The intermarriage of different races is a prolific cause 
of irregularities of indirect heredity. 

Dr. Talbot 1 defines as constitutional irregularities "those that 
develop with the osseous system," such as those due to excessive devel- 
opment or to lack of development of either the upper maxillary, inter- 
maxillary, or lower maxillary bones, or of the ramus or body of the 
latter ; too high vault, too narrow vault, etc. 

1 Etiology joJ Osseous Deformities of Head, Jaws, and Face, 3d ed. p. 16. 



ETIOLOGY OF DENTAL IRREGULARITIES. 691 

A constitutional irregularity may be hereditary or may be due to 
some cause affecting the osseous system, such as lack of development 
of the bones about the nasal cavity from lack of circulation of air 
through this cavity and connecting sinuses, due to mouth-breathing. 
The result may be a high vault with a small and narrow arch, and 
consequent crowding and various irregularities of the teeth. 

An acquired irregularity may be due to — 

(a) Too long retention of deciduous teeth. 

(6) Too early extraction or loss of deciduous teeth. 

(c) Injudicious extraction or early loss of permanent teeth. 

(d) Delayed eruption of permanent teeth. 

(e) Pernicious habits (thumb-sucking, etc.). 

(/) The presence of supernumerary teeth, etc. (See page 697.) 

Fig. 607. 




Lingual eruption of permanent incisors due to too long retention of deciduous incisors. 

Too long retention of deciduous incisors may cause lingual eruption 
of permanent incisors (see Fig. 607) or rotation of the same. 

Too long retention of deciduous canines may cause either lingual 
eruption (Fig. 700) or labial eruption of permanent canines (608). 

Too long retention of deciduous molars may cause a constricted arch 
(Figs. 609 and 610; also page 785). 

(a) Long Retention of Deciduous Teeth. — A tooth may be deflected 
from its normal position in erupting by the presence of a supernumerary 
or deciduous tooth the root of which has not been absorbed. Death of 
the pulp of a deciduous tooth will prevent its normal or physiological 
resorption. It may then be removed by a pathological process which 
is much slower, or it may not be removed at all, but remain indefinitely, 
or till removed by the forceps. 

(6) Too Early Extraction of Deciduous Teeth. — As Nature pro- 
vides for the shedding of the deciduous teeth at the proper time, inter- 
ference by extraction should be avoided in all possible cases. 

Unless the deciduous teeth are retained, the natural expansion of the 



692 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

Fig. 608. 




Labial eruption of permanent canines due to too long retention of deciduous canines. 

Fig. 609. 




Figs. 609 and 610 : Semi-constricted arch due to too long retention of deciduous molars. 



ETIOLOGY OF DENTAL IRREGULARITIES. 693 

jaw by interstitial growth will be interrupted. When a deciduous tooth 
is extracted, the contiguous teeth, whether deciduous or permanent, 
tend to move toward each other and occupy the space which should be 
preserved for the succeeding tooth. 

But one rule is needed, as follows : Extract a deciduous tooth only 
when it deflects its successor. 

Rules against Extraction of Deciduous Teeth. — 1. Do not 
extract a deciduous lettered to make room for a permanent central incisor. 

2. Do not extract a deciduous canine to make room for a permanent 
lettered incisor. 

Requests for such extraction will often be made by the parent, to 
whom the explanation should be made that such extraction is liable to 
prevent the natural growth of the jaw for the accommodation of the 
permanent teeth ; also that, while the six anterior deciduous teeth are 
replaced by larger permanent ones, the four temporary molars in each 
jaw are replaced by the smaller bicuspids, and that when this takes 
place, irregularities of the incisors, especially the lower ones, will cor- 
rect themselves, unless the teeth are too large for the jaw, which cannot 
be foretold with certainty at this age. Even if it could, no extraction 
of deciduous teeth would be of benefit, but rather positive harm. 

3. Do not extract a deciditous second molar till the first permanent 
molar is firmly fixed in place, and not then unless the second bicuspid 
has erupted or is about to erupt out of position. 

Requests for extraction of deciduous molars are made on account 
of cavities of decay, which should be filled and the teeth preserved for 
service in mastication. 

The only exception to these rules is in cases of incurable alveolar 
abscess, which may endanger the alveolar border and the tooth forming 
beneath. 

(c) Early Loss of Permanent Teeth. — Irregularities may be due 
also to early loss or injudicious extraction of permanent teeth. 

An early loss of first permanent molars may cause upper or lower 
protrusion. 

An early loss of lateral incisors causes a narrowing of the anterior 
portion of the arch and deprives the angles of the mouth of their 
proper contour. 

A loss of canines causes a depression of the angles of the mouth and 
wing of the nose. 

(r/) Delayed Eruption of Permanent Teeth. — The delayed eruption 
of any permanent tooth, after the loss of its deciduous predecessor, will 
allow the teeth on each side of the space to move toward each other and 
thus prevent eruption, or crowd the erupting tooth out of the line either 
labially or lingually. 



694 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



It is often of the utmost importance to ascertain whether a tooth is 
delayed in eruption or is permanently absent. The tooth most likely 
to be absent is the third molar. The one next most likely to be absent 
is the lateral incisor, generally referred to as the " missing lateral." 

In case the permanent laterals do not erupt at the proper time, the 
question often arises with a crowded arch, whether to preserve space 
for them in hopes of their eruption, or to allow the other teeth to crowd 
along and occupy the space. Hitherto it was impossible to answer this 
question, but lately science has come to our aid, and by the skiagraph 
the uncertainty can be made a certainty. 



Fig. 611. 



Fig. 612. 





Figs. 611-614, and the following description 1 by Dr. J. N. M'Dowell, 
will illustrate the subject of delayed eruption : 



Fig. 613. 



Fig. 614. 





" Fig. 611 shows the models of a boy eight years old. The space 
for the laterals is entirely closed up. The teeth in both the upper 
and lower arches were regulated, making the necessary room for the 
laterals in the upper arch (see Fig. 612). This space was retained for 
two years, and at the end of that time there was still no sign of the 

1 Dr. J. N. M'Dowell, Dental Cosmos, March 1900, vol. xlii. p. 237. 



ETIOLOGY OF DENTAL IRREGULARITIES. 



695 



laterals. Examination gave no indication of delayed teeth, but the 
result of the z-ray (Fig. 613) showed the laterals high up in the 
process still only partly developed. It was several months later 
before there were any indications of the laterals making their appear- 
ance. Fig. 61-4 shows the same case eight months after the s-ray was 

taken." 

Oftentimes the occlusion is sadly impaired by the non-eruption of 
a bicuspid impacted between contiguous teeth. The skiagraph Fig. 
615 reveals the exact position of the delayed tooth and shows the im- 
portance of making room for its eruption. Fig. 616 shows a second 
bicuspid caught under the shoulder of a first bicuspid, and suggests that 
it can be released by forcing the latter into an upright position. 

The exact position of a delayed canine may be revealed, and the 
question settled whether it be possible for it to erupt without assistance, 
or whether it can even be forcibly erupted. 



Fig. 615. 



Fig. 616. 





In some cases a deciduous tooth remains in place long after the time 
when it should have fallen out. It may be so firm as to cause serious 
doubts about the advisability of extracting it, even though there is mal- 
occlusion while it is in place. The skiagraph will reveal the presence 
or absence of the bicuspid, and show whether extraction should be 
resorted to or not. 

The method of making the skiagraph is thus described 1 by C. 
Edmund Kells, D. D. S., of New Orleans : 

" One of the requirements in obtaining a skiagraph is that the object 
to be pictured and the plate or film must be held perfectly still during 
the process. It is frequently possible to cut the film the proper shape, 
inclose it in a black (light-proof) envelope, and allow the patient to 
hold it in the mouth in the desired position ; but on general principles 
this is not satisfactory, more especially with children, as it is liable to be 
moved during the exposure. 



1 Dental Cosmos, October 1899, vol. xli. p. 1014. 



696 ORTHODONTIA AS AN OPERATIVE PROCEDURE 

" The method now employed, after much experimenting in that line, 
is as follows : 

" A cast is made of the portion of the mouth to be skiagraphed, 
and a small piece of modeling compound moulded over the crowns of 
the teeth thereon. A piece of aluminum (this metal being almost 
transparent to the rays) of about 26 or 28 gauge is cut to the desired 
size and shape and bent to fit the cast as well as possible. This is 
slotted along the edge toward the crowns of the teeth, and thereby 
attached to the modeling compound referred to above. This forms 
a convenient little film-holder, which when placed in the mouth will 
allow the patient to close the teeth upon it, and thus hold it securely 
in position, without danger of its moving, for a much longer time than 
is necessary to take the picture. 

" The next step is to cut the plate or celluloid film, whichever is to 
be used, to the proper size and envelop it neatly in black paper, gluing 
down all the edges with paste, and securing it to the plate-holder by 
two or more small aluminum clamps. 

" This is all that is usually necessary : but if it is deemed advisable 
to protect the envelope from moisture, as is sometimes the case, more 
especially for lower teeth, then it is covered with thin tin foil or 
waterproof paper neatly pasted down, care being taken not to have the 
foil (if that is used) doubled upon the side to be exposed. While this 
may appear to be a long process, it is quickly accomplished, and the 
invariably satisfactory results obtained warrant the trouble taken. 

" The patient is then seated in a chair with a photographer's head- 
rest to hold the head, the Tesla screen put in place, and the tube brought 
to about ten or twelve inches from the face and placed so as to throw 
the best shadow of the parts upon the film. The length of exposure 
depends upon the thickness of the parts to be penetrated, the working 
condition of the apparatus, and the distance of the patient from the 
tube, the time being proportional to the square of the distance. From 
sixty to ninety seconds are necessary for ordinary cases, ranging perhaps 
up to one hundred and twenty seconds for third molars and heavy jaws, 
while twenty to forty seconds are sufficient for some favorable cases in 
thinner bones." 

In some of the large cities skiagraphs can be readily obtained from 
experts with the Rontgen ray, who make it a business to accommodate 
physicians and others desiring their services. Any expert dentist with 
a slight knowledge of photography can readily prepare the film for the 
purpose. 

(e) Pernicious Habits. — The habit of thumb-sucking may cause 
upper protrusion (see Fig. 757), lack of anterior occlusion (Fig. 801), 
or a constricted arch (Fig. 798). 



ETIOLOGY OF DENTAL IRREGULARITIES. 697 

The habit of sucking the finger or lip may cause protrusion of either 
jaw according to the position of the finger or lip. 

While thumb-sucking sometimes causes the irregularities mentioned, 
it is not a frequent cause, and it is a singular fact that the habit does 
not cause irregularity of the deciduous teeth. 

The habit of mouth-breathing, whether owing to nasal obstructions 
or not, may cause lack of anterior occlusion — see (e), page 786 — or 
apparent lower protrusion — see (e), page 774. 

(/) Other Causes of Irregularity. — Obstruction of the nasal cavity 
by a deflected septum, enlarged turbinate bones, polypi, adenoid growths 
in the nasopharynx, enlarged tonsils, or any other cause, by preventing 
free circulation of air through the nasal cavity, may be the cause of a 
lack of development of the frontal, sphenoidal, ethmoidal, and maxil- 
lary bones. This lack of development may produce a high and con- 
tracted vault, with a narrow and small arch and consequent crowding 
of the teeth into various irregularities. 

Lack of development of the intermaxillary bone may cause (a) a pointed 
arch (page 757), (6) lack of anterior occlusion (page 786), or (c) prom- 
inent canines and depressed laterals — see (a), page 745. 

Disparity in size between the teeth and the jaw may be due to either 
of two widely different causes, and yet produce several similar irreg- 
ularities. 

(1) This disparity in size may be due to teeth too large for the jaw 
(indirect heredity — page 690). 

(2) It may be due to premature loss of deciduous second molars and 
a forward movement of the permanent first molars, thus shortening the 
arch and making it too small for the ten teeth that are to occupy it. 

The result may be — 

(a) Prominent canines and depressed laterals (Class 7, page 745). 

(b) Pointed arch (Class 8, page 757). 

(c) Upper protrusion (Class 9, page 760). 

(d) Constricted arch (Class 12, page 784). 

(e) Lower protrusion (Class 10, page 773). 

The same condition in both jaws at once may cause similar irregu- 
larities in both jaws. One of the most notable of these is double pro- 
trusion (Class 11, page 782). 

Loss of the deciduous second molar on one side may cause any of 
these irregularities on that side only, such as a semi-constricted or 
semi-pointed arch. 

Changes in Surrounding" Tissues when Teeth are Moved. — 
1. Resorption and Deposition. — When a single tooth is moved in 
any direction, there is first a compression of the soft and then of the hard 
tissues in front of the tooth, and at the same time a stretching of the 



698 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

peridental membrane behind the tooth. This is succeeded by resorp- 
tion of the hard tissues in front by osteoclasts and & formation of new 
bone by the osteoblasts behind the moving tooth. 

This latter action is much slower than the former, and depends on 
the tooth being held firmly in its advanced position. Any slight return 
will interfere with the formation of new tissue, and a tooth repeatedly 
moved forward and allowed repeatedly to recede will never become firm. 

When a tooth is rotated in its socket, there must be a stretching 
of the fibers of the peridental membrane. If the fibers had not con- 
siderable elasticity, those opposing the rotation of the teeth would be 
ruptured instead of stretched, and would not tend to twist the tooth 
back to its old position. A tooth is sometimes forced back by the pres- 
sure of adjoining teeth, but such contingencies are not here under con- 
sideration. If the root is curved or is not round, there may be some 
resorption and rebuilding of the walls of the alveolus. 

2. Bending of the Alveolar Ridge. — When several teeth are 
moved in the same direction at the same time there is a movement of 
the alveolar ridge as if it were a semi-plastic mass. This movement is 
easily proved by the following observations : 

After a case of upper protrusion is reduced the labial portion of the 
alveolar ridge appears no thicker than before. If the only movement 
were of the roots through the ridge by resorption in advance of the 
moving tooth and formation of new bone behind, the labial portion 
would remain as prominent as before. 

In spreading the arch rapidly, if movement took place only after 
resorption, the teeth might be pushed out of the ridge, but the external 
plates of the alveolar process will be found no thinner than before, 
while the vault of the palate is perceptibly broadened. 

Dr. C. S. Case says that when teeth and roots are moved forward, 
sometimes ridges will appear on the outer surface of the alveolar 
process, but that the spaces or hollows between will soon fill up so as to 
present an even surface. 

3. Separation of the Superior Maxillae at the Symphysis. 
— When strong pressure is applied upon molars and bicuspids to spread 
the arch the superior maxillae may be separated at the symphysis. (See 
Figs. 617 and 618.) 

Such separation was first recorded by Dr. E. C. Angell of San Fran- 
cisco 1 in 1885, and has been noticed by Guilford, Black, Talbot, Farrar, 
Ottolengui, and others since. Drs. Talbot 2 and Ottolengui 3 regard it 
as an advantage as giving room for re-arranging crowded incisors more 

1 Dental Cosmos, vol. ii. p. 540. 

2 Discussion in World's Columbian Dental Congress, vol. ii. p. 722. 

3 Dental Practitioner, vol. xxxv., No. 4, October 1894. 



ETIOLOGY OF DENTAL IRREGULARITIES. 699 

Fig. 617. 




Symphysis of superior inaxillee, before spreading arch. 

quickly than in any other way and maintaining crowns and roots in an 
upright position. 

Fig. 618. 




Separation of superior maxillae at symphysis, after spreading arch. 

4. Depression of the Roots ix the Sockets. — In reducing 
cases of lack of anterior occlusion by means of elastics extending from 
a chinpiece to a cap to the top of the head, Prof. Guilford x says : 
" The condyles of the lower jaw will be tipped somewhat out of their 
cavities, and the latter be partially filled up with new ossific material ; 
at the same time the tendency will be to shorten the posterior occlud- 
ing teeth by forcing them farther into their sockets." 

Charles S. Tomes 2 in a similar case questioned whether " the closure 
of the front teeth was effected by an elongation of the ascending 
ramus of the jaw or by the antagonizing teeth being depressed and, so 
to speak, forced farther into their sockets," and concludes, " I am 
inclined to think the latter is the true explanation." 

1 Orthodontia, 2d ed., p. 196. 2 Kingsley's Oral Deformities, p. 121. 



700 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



Pathological Conditions which may be Caused by 
Irregularities of the Teeth. 

Under this head may be mentioned dental caries, gastric disorders, 
and deposition of salivary calculus. 

Caries. — In the normal arch the teeth touch each other at one point 
only, and fluids are freely circulated between and about them by the 
tongue, lips, and cheek. When the teeth are irregularly arranged broad 
surfaces often come in contact, the convex surface of one incisor may 
be partially imbedded in the concave surface of another, or three teeth 
arranged as in a triangle form between them a cul-de-sac. In all such 
cases the maintenance of cleanliness is difficult if not impossible, and 
caries is the probable result. 

Dyspepsia. — Any deviation from the normal arch will cause also 
a deviation from the normal occlusion, so that proper trituration of the 
food is interfered with if not positively prevented. Such lack of 
thorough mastication will throw unusual burdens upon the digestive 
organs, resulting in their greater or less derangement. 

The question of occlusion is exceedingly important, and often decides 
the method of treatment of an irregularity or of making room, or of 
undertaking any treatment whatever. 

In most cases of complicated irregularity there is already mal- 
occlusion of the masticating teeth, and every endeavor should be made 
to move the teeth, so as to improve the occlusion and make it as nearly 
normal as possible. 

When the occlusion is already normal and the irregularity is slight 
but cannot be reduced without seriously deranging one or both sides of 
the mouth, it may be best to permit the irregularity to remain, as the 
least of the two evils. 

In any case of widening or spreading, should either arch be made too 
wide for the other, that also should be spread to restore or improve the 
occlusion. 

If either arch be too small for the other, the sole object in spreading 
may be to improve the occlusion. 

If in any case room must be made by extraction, the most serious 
consideration must be given to the choice of the tooth or teeth whose 
removal will least derange the occlusion, if already good ; and if other- 
wise, selection may be so made as to improve it. 

The tooth most often under discussion in this respect is the perma- 
nent first molar. This is a very valuable tooth for mastication, and its 
loss may render all the teeth on that side of the mouth useless for that 
function. The teeth back of the space may tip forward and those ante- 
rior to it may tip backward, so that they all present only points and 



ACCIDENTS WHICH MAY HAPPEN DURING TREATMENT. 701 

cusps to the cusps of opposing teeth, instead of the normal interlock- 
ing of cusps which gives the greatest efficiency. 

The question as to the extraction of a tooth will depend also on 
its condition. In the writer's opinion it will be better in many cases 
to crown the roots of a molar decayed too much for filling, and remove 
some other tooth that is less useful in mastication. (This question is 
further discussed on page 745.) 

Salivary Calculus. — As the accumulation of salivary calculus is 
impossible upon parts of the teeth subjected to use in mastication or 
easily cleansed with the brush, so any abnormality of arrangement that 
prevents thorough use of the brush favors the deposit, with all of its 
possible consequences. 

Accidents which may Happen during Treatment. 

Death of the Pulp. — This may occur from strangulation at the 
apical foramen from too rapid movement of the tooth. The possibility 
of this accident is least when movement is begun while the apical fora- 
men is large, before the root is completely formed ; it increases with the 
age of the patient, and is greatest after the root is fully formed and the 
foramen is constricted to its permanent size. 

Death of the pulp may also occur from rupture of the bloodvessels 
at the apex of the root from too rapid elevation of the tooth. The 
liability of such accident will vary according to the age of the patient 
and size of the apical foramen. 

Rupture of the Pericementum. — This may occur also from too 
rapid elevation of a tooth. After such an accident, a tooth returned 
to its socket would be in the condition of a replanted tooth, subject 
to the same chances of attachment and retention. 

Permanent Enlargement of the Alveoli. — Dr. Talbot ] says : 
" The probability of a perfectly satisfactory result in regulating 
decreases yearly after the age of puberty, and after the age of twenty- 
six the chances of a really satisfactory result are very meagre, for at 
this time the entire osseous system is fully developed and there is little 
probability of extensive deposit of ossific material." 

The writer would, however, fix the date later than that — perhaps 
at thirty years. 

Pressure at any age will cause resorption, therefore teeth may be 
moved in the case of adults, though more slowly on account of the greater 
rigidity of the alveolar process. Greater force will be needed to produce 
resorption in advance of the moving tooth, and there is a possibility, 
even a probability, that no ossific deposit will take place behind the 

1 Irregularities of the Teeth and their Treatment, 2d ed., p. 172. 



702 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

root. The result is an enlarged socket in which the tooth never again 
becomes rigid. 

Permanent enlargement of the alveoli may occur also from not 
retaining teeth fixedly in their new position but allowing them to move 
back and forth. The action of the osteoblasts in forming new bone is 
thus interfered with so much as to absolutely prevent it, and the result 
is an enlarged alveolus. 

Injury to the Enamel (Caries). — This may occur from too long 
retention of either regulating or retaining appliances in contact with 
the teeth. 

Bands that are to be retained more than a few weeks should be 

cemented upon the teeth and carefully watched, as a loose band will 

Fig 619 surely result in a softening of the enamel under 

it, sometimes even to the extent of forming a 

cavity. 

Retaining appliances should be so constructed 

Round and flat contacts that no flat or broad surfaces remain in contact 
in regulating fixtures. with the teeth. A round wire is as efficacious 

as a flat bar, and the tooth under it is easily kept clean, as the point 

of contact is so small. (See Fig. 619.) 

Appliances, Materials, Methods, and Forces Employed. 

Definitions. — To prevent repetitions a few appliances and materials 
will be briefly described. 

Rubber Band. — A section cut from French rubber tubing from 
•|- to J of an inch in diameter and from -fa to -J- of an inch wide. (See 
Fig. 620.) These lose their elasticity by remaining stretched, and should 
be changed at least twice a week. 

Fig. 620. 




Ill 




Bicuspid. Molar. 

Rubber tubing for bands. Adjustable bands (Angle). 

Gauge. — In indicating the thickness of plate and size of wire the 
number referred to is that of B. & S. gauge, e. g. wire No. 20, plate 
No. 27, etc. 

Tube or Tubing. — Made of a strip of platinum-gold or German 
silver No. 27 to No. 32 gauge and J of an inch or less wide, drawn 
through successive holes in a draw-plate until a tube is formed and 
reduced to the desired size. (See Fig. 628.) To make a tube to fit any 




APPLIANCES, MATERIALS, METHODS, AND FORCES EMPLOYED. 703 

desired wire or screw, take a strip three and one-third times the diam- 
eter of the wire or screw. 

Magill Band. — The invention of Dr. W. E. Magill. A strip of 
platinum, gold plate, or German silver, No. 30 to 36 B. & S. gauge, 
preferably the latter, from ^ to -J- of an inch wide, 
bent around a tooth in the mouth or on a plaster cast, ^ IG - 622# 

and soldered at the overlapping ends. This is cemented 
to a tooth with zinc phosphate. (See Figs. 622, 647, 
et seq.) 

Adjustable Band (Angle's). — A band of German silver from 
\ to \ of an inch wide and No. 36 B. & S. gauge, to one end of which 
is soldered a short tube and to the other a screw, which is passed 
through the tube and tightened around the tooth with a nut. (See 
Fig. 621.) Cement should be placed inside the band before apply- 
ing it. 

Band Ribbon. — This is best made from platinum or German silver 
wire No. 13, rolled to No. 34 or No. 36 plate. This is tougher than 
when cut from plate of the same thickness. For the anterior teeth the 
writer often uses, however, gold-faced platinum rolled to the gauge 
mentioned. It has the strength of platinum and the color of gold, 
which is preferred by many patients. 

To this band may be soldered a tube, hook, screw, or any appliance 
desired. 

Jack-screw (Angle's). — A tube pointed at one end, in which is 

inserted a screw about No. 16 B. & S. gauge, 
Fig. 623. . . & & 

' with a nut resting on the open end of the tube. 

The end of the screw is flattened or bifur- 

Angles jack-screw. 

cated. The length of the tube determines 
the length of the jack-screw. (See Figs. 623 and 643.) 

Drag-screw (Angle's). — A wire ^ „„, 

bent at right angles at one end, 
threaded at the other with a nut. (See 
Fig. 624.) 

Piano Wire. — Piano strings. Steel 

. ° Angle s drag-screw. 

wire, elastic, yet soft enough to bend 

easily with pliers, from No. 20 to No. 24 B. & S. gauge : used for 
springs and elastic levers. (No. 20 B. & S. gauge corresponds to 
about No. 15 of piano wire gauge.) 

Ligatures. — Floss silk well waxed. 

Twisted Ligatures.— Twisted silk No. A or 00 or linen thread 
unbleached No. 50, well waxed. 

These are very useful in moving teeth, either ligated directly on the 
teeth or in connection with other appliances. When tied tightly from 




704 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



one tooth to another there is an immediate movement by slight com- 
pression of the peridental membrane ; then as the twisted fibers swell 
the ligature is shortened and more pressure exerted. 

It is to be understood that in the majority of illustrations in this 
chapter in which rubber bands are shown as the moving force, ligatures 
may be substituted. They should be renewed every day or two. 

Twisted wiee ligatures of platinum, copper, brass, or German 
silver wire are excellent for intermittent movement of teeth. Dr. Angle 
suggests No. 28 B. & S. gauge as the best size (Figs. 726 and 727). 

Norton-Talbot or Coil Spring. — A spring of piano wire No. 
20 to No. 24 B. & S. gauge coiled upon itself one or more times. 

Fig. 625. 




Talbot springs. 



The best size of coil is that made around a piece of the same wire. 
(See Figs. 625, 741, and 742.) 

Matteson Spring. — A spring of piano wire No. 20 to No. 24 B. & 
S. gauge, with two coils a half-inch or more apart. (See Figs. 626, 651, 
and 744.) 



Fig. 626. 



Fig. 627. 



Fig. 628. 



f~\ 



Matteson spring. 




Swaged caps. 



Metallic tubing. 



Cement. — Zinc phosphate is more adhesive than oxychlorid of zinc ; 
it should be mixed thin and applied to the tooth and band or cap. 
Eubber dam should, if possible, be applied to the teeth before using 
the cement. 

Swaged Caps (Matteson's). — Caps swaged to fit over the whole 
or part of a tooth and secured with cement. To these caps are soldered 
hooks, bars, tubes, levers, etc. (See Fig. 627.) 



APPLIANCES, MATERIALS, METHODS, AND FORCES EMPLOYED. 705 

Lock-nut. — A second nut screwed up against the first — neces- 
sary in some cases to prevent retrograde action by the patient's 
tongue. 

Labial Bow. — A bow of stiff wire, German silver, or clasp gold, 
about No. 16 B. & S. gauge, extending from the buccal surface of the 
teeth on one side of the mouth around the arch to a corresponding posi- 
tion on the other side. It may be held in place by inserting the ends 
in a plate (Fig. 711) or in tubes soldered to bands cemented on suitable 
teeth (Figs. 713, 729, 759). The ends of the bow may be screw-cut 
and furnished with nuts, as shown in these figures, or bent in bayonet- 
shape (Fig. 741). 

Lingual Bow. — A similar bow on the lingual surface of the arch, 
with the ends inserted in tubes on the lingual surface of bicuspid or 
molar bands, screw-cut with nuts (as in Fig. 715 or 716) or bent into 
hooks (as in Fig. 667). 

Labial and lingual bows are often used advantageously together 
and attached to the same teeth, as in Fig. 669 or 713. 

Author's Partly- made Appliances. — Fig. 629 shows the writer's 
system of partly-made appliances. Each consists of a piece of band- 



Fig. 029. 




G H 

Partly-made appliances. 



ribbon bent into an open loop. To each is soldered a tube, hori- 
zontal or crosswise, round or flat, or a wire, in line or at right angles. 
These can be made by the practitioner in leisure moments, and kept 
in stock. When a patient is in the chair, one of the open bands can 
be bent around any tooth, with the tube or wire in any position de- 
sired. The open ends can then be drawn tightly around the tooth 
and the sides burnished to fit accurately. Remove the band, cut the 

45 



706 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



ends as shown in Fig. 630, A, bend one over the other, as in b, 
pinch them tightly together, so as to hold while soldering. Grasp the 
band with the pliers as shown in Fig. 631, and apply solder and 
heat to the inside of the joint. The pliers will protect the tube or 



Fig. 630. 





A, Band fitted ; B, ready for soldering. 



wire from unsoldering. The surplus ends can then be cut away, as in 
making a plain band. E, in Fig. 629, shows two open bands soldered 
to a long tube for making a double anchorage appliance, such as 
shown in Fig. 730. D has a flat tube, which may be used as in Fig. 



Fig. 631. 




Soldering joint in open band. 



739. F will make a retainer, like Fig. 653 or 677, while G and H 
can be bent into hooks for various purposes. 

The writer finds these " partly-made appliances " a great saving of 
time, as a great variety of complete appliances can be made from them 
while the patient is in the chair. 

Figs. 745 and 746 show how an expander can be made in a similar 
manner. 

Force. — "Constant Force" — That exerted by compressed rubber 
or a spring of clasp gold or piano wire. 

" Intermittent Force" — That exerted by a screw, which allows 
periods of rest after each application ; also that exerted by compressed 
wood or twisted ligatures of silk or linen. 



APPLIANCES, MATERIALS, METHODS, AND FORCES EMPLOYED. 707 

Methods. — Xo one " method " is applicable to all cases, so that it is 
necessary to select from various methods the simplest and most efficient 
for treating each kind of irregularity. During the last twenty years 
there have been presented by specialists in orthodontia many different 
plans of regulating. These are known as their special " methods " aud 
are designated by the names of their originators. 

The first extensive description of regulating appliances was that 
by Dr. Norman ^Y. Kfngsley, in his book on Oral Deformities, 
in 1880. Most of the appliances described in his book were taken 
from original articles previously written by him for dental jour- 
nals, while a number were selected from articles by other well-known 
writers. 

The first to claim a distinct method or system was De. J. N. Fa rear 
in articles published about 1875, and further elucidated in book form 
in 1888. His system is based upon the adoption of the screw as a 
motive force. The originator claims the screw to be the only force 
which should be used, because it is intermittent and gives the parts a 
period of rest after each application. Very ingenious devices have been 
invented by him by which the screw is applied successfully to all kinds 
of movement, but as a rule his appliances are more complicated than 
those of any other system. 

The Coffin method was introduced at the International Medical 
Congress in London, in 1881, by Walter H. Coffin. The elasticity of 




Coffin split plate for spreading the upper arch. 

piano wire is used as a motive force, by anchoring it in vulcanite plates. 
The most notable example of this method is the Coffin split plate for 
spreading the arch. (See Figs. 632, 633, and 634.) 

The Angle method depends chiefly on the screw for force, though 
piano wire and twisted wire ligatures are also used. 

Dr. Angle was the first to advocate extensive use of German silver 
for regulating appliances. The advantages of this alloy are such that 
it now is more largely employed than any other material. 



708 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



A new application of force has been lately introduced, viz. the 
elongation of wire by pinching or compressing it with special round 



Fig. 633. 



Fro. 634. 





Coffin spring plate for lower arch. 



Coffin spring plate for single teeth. 



pliers, shown in Fig. 676. This may be used in many places instead 
of the jack-screw. 

The construction of jack-screws and drag-screws has been greatly 
simplified. Thin soldered bands are cemented to the teeth, or " anchor 
bands," the ends of which are united by screw and nut. To these 
bands tubes are soldered for the attachment of appliances which are so 
constructed that force once applied need not be withdrawn till the en- 
tire movement is accomplished. A rest may be allowed, but no back- 
ward movement. Thus no interference is made with building up the 
tissues behind the tooth. 

Appliances, complete or in parts, to be adapted to special cases have 
been put on the market by Prof. Angle. These more nearly fill the 
want of one who cannot make all his appliances. 

Dr. V. H. Jackson's method consists in the use of piano wire or 
other elastic wire for force and the attachment of the wire to the teeth, 
in most cases, by means of a " crib " made of the wire itself, and not 
by means of bands or plates. 

For full descriptions of these methods the student is referred to the 
writings of the authors themselves. 1 

General Directions. 

All metallic bands which are to remain in contact with the teeth for 
any length of time should be cemented to them with zinc phosphate, to 
prevent deleterious action of acids of fermentation which would be gen- 
erated and retained between bands and teeth. The rubber dam should 
be applied whenever possible to the tooth to be banded, and to one or 

2 In the American Text-Book of Prosthetic Dentistry, edited by Dr. Charles J. Essig, 
will be found a chapter on " Orthodontia Technic," by the writer, in which the making 
of regulating appliances is described much more fully than is possible here. 



GENERAL DIRECTIONS. 709 

more teeth on each side. In some cases it may be applied to fourteen 
teeth at once. The teeth should be thoroughly dried and cleaned ; the 
cement mixed thin is applied to the tooth and to the inside of the band, 
and the latter is pushed or malleted firmly to place. The teeth should 
be kept dry for ten minutes or longer after the cement is applied. If 
this is not possible, where napkins are used, varnish or melted paraffin 
may be applied over the cement at the edges of the band for the pur- 
pose of excluding moisture as long as possible. Bands may be fast- 
ened in a similar way by chloro-percha. 

During the time of regulating and while retaining appliances are in 
position, bands should be examined frequently. If one becomes loose 
it should be removed, and cemented on again. 

The patient should keep a brush at the office for use when appli- 
ances are removed, and the appliances should be very carefully cleansed 
by the operator before they are replaced. When plates are used espe- 
cial care should be taken. 

During the time that immovable appliances are worn, the patient 
should be provided with a bulb syringe with which dilute listerine or 
other antiseptic mouth-wash can be thoroughly applied under bars, 
screws, springs, etc., or wherever the brush cannot reach. 

Teeth should generally be moved a little farther than the desired 
position, because there is almost always a slight return of the tooth 
toward its old position after the retaining appliance is removed. This 
retrograde movement is less likely to occur with canines when room has 
been made by extraction. 

The age at tchich correction should be begun depends on the presence 
of sufficient teeth for anchorage. It should be commenced as soon as 
appliances can be used to advantage. 

The writer believes in early correction, in some cases as early as the 
age of seven years. The advantage of early correction is that the 
alveolar process is less rigid and the alveoli larger than when the child 
is older, and hence less resistance is offered. At the age mentioned the 
deciduous molars are firm, and in some cases remain so until the child is 
ten or twelve years of age. (Seepage 712 and following pages for cases 
that demand early treatment.) At an early age new tissue is built up 
around the tooth more quickly, as the osteoblasts are in a more active 
condition; hence retaining appliances need not be worn so long. 

Teeth tend to move into their proper positions if room is made for them. 
This seems especially true of the canines. In many cases after extrac- 
tion of a first bicuspid the canine will move to its place without assist- 
ance. (See Figs. 723 and 724.) 

Sufficient explanation should be made to the child to overcome any 
dread or fear which may have been engendered. 



710 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



The parent or guardian should see that the child follows the opera- 
tor's directions carefully, and should be given instructions as to the 
course to pursue in case any appliances become dislodged. When screws 
are used an intelligent parent or guardian may assist by turning them 
according to instructions. If the patient is old enough, and desirous of 
aiding, he may be intrusted with such duties. Screws or nuts should be 
given about half a turn twice a day. 

Rubber bands should be renewed at least twice a week. Piano-wire 
springs should have their force renewed by bending (or straightening), 
about twice a week. 

Silk or linen ligatures should be renewed daily or at least every 
other day. They should be well waxed, as then they are applied more 
readily. Moisture soon penetrates the wax and swells the fibers, pro- 
ducing pressure in the direction intended. 

Wire ligatures should be twisted daily (Figs. 726 and 727). 

The amount of force which may be used will vary with individuals. 
When a new appliance is used, no force should be applied for a few 
days, till the patient becomes accustomed to the apparatus, then slight 
force may be applied, and increased after a few days, but in no case 
should excessive force be used. That is, in no case should force be used 
strong enough to cause continued pain or loss of sleep, nor should it 
make the teeth " tender " enough to prevent mastication. 

Impressions should be taken of the teeth of both jaws in all but very 

Fig. 635. 




Angle's impression tray. 



simple cases. Trays with high sides and flat floor should be used. 
Those designed by Prof. Angle are especially adapted to the purpose 
(Figs. 635 and 636). 

Modeling compound is best adapted for impressions of most 
cases. It should be placed in cold water and slowly heated in order to 



GENERAL DIRECTIONS. 711 

soften it uniformly. It should not be used hot enough to be painful to 
the patient. Warm the tray before filling it so that the impression 
material may adhere to it when it is removed from the mouth. When 
the compound has been placed in the mouth and pressed against the 
teeth, draw the lip over the edge of the tray, and press on the lip so as 

Fig. 636. 




Angle's impression tray. 

to force the material as far up on the ridge as possible, thus obtaining 
an impression of the alveolar Avails. 

Special cases may need the more absolute accuracy of plaster-of- 
Paris, but such cases are rare. 

Avoid an excess of material in the palatal portion of the tray, as the 
surplus pressed backward is apt to drag at the necks of bicuspids and 
molars. When the material has been pressed into correct position, 
apply cold water with a syringe to the tray and under the lip and 
cheeks till the material is hard. 

Casts made from these impressions should be articulated either with 
wire hinges or by extending the rear portions, and preserved for fre- 
quent examination. If the casts are held together by a " plaster articu- 
lator,' 7 it should be open in the rear, so that the lingual surfaces and 
cusps of the teeth can be examined while the teeth occlude. An extra 
cast will often be needed, on which to make appliances. During treat- 
ment, casts should be made at interesting stages to record progress. 

Before deciding upon treatment study the case in action and repose ; 
observe the movements of the lips in speaking and laughing ; notice 
how much the gums are disclosed, if at all, or with what difficulty the 
teeth are covered by the lips. Study the profile. If the irregularity 



712 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

affect the contour of the lips, have a photograph taken which will show 
the profile, or take impressions of the lips, nose, and chin, or of the 
whole face, with plaster. 

Study the casts also before deciding on the treatment or appliances. 
In some cases make an extra cast, cut off the malposed teeth with a 
thin saw and re-arrange them in normal relationship. Much may be 
learned by such means. 

Classification of Irregularities. 

Aberrations from the normal arch are almost numberless, and almost 
every writer adopts a different nomenclature to express the malpositions 
that he wishes to describe. 

In speaking of single teeth, it seems the best plan to describe their 
positions in relation to the normal curve or arch (Fig. 599) or the lines 
of normal eruption (Fig. 600). Thus, a tooth erupted within the normal 
arch is well described by the term lingual eruption, or as a tooth erupted 
lingually. A tooth erupted outside the normal arch is well described by 
the term labial eruption, or as a tooth erupted labially. A tooth in the 
normal line, but turned on its own axis, is rotated. 

For convenience in description, irregularities are here arranged in 
fifteen classes. The first six have reference to single teeth, and nearly 
all the rest to the arches as a whole in relation to each other and to the 
contour and profile of the face. 

1. Lingual eruption : A tooth erupted lingually. 

2. Labial eruption : A tooth erupted labially. 

3. A tooth rotated. 

4. A tooth extruded. 

5. A tooth partially erupted. 

6. Several teeth in any or all of these positions. 

7. Prominent canines and depressed laterals. 

8. Pointed arch. (V-shaped.) 

9. Upper protrusion. 

10. Lower protrusion. 

11. Double protrusion. 

12. Constricted arch. (Saddle-shaped.) 

13. Lack of anterior occlusion. 

14. Excessive overbite. 

15. Separation in the median line. 

Class 1. Lingual Eruption : A Tooth Erupted Lingually. — The 
operations and appliances presented for the first four classes are for single 
teeth, but they will apply in most cases to two or more teeth in the same 
malposition. In Class 6, appliances will be described which are better 
suited to several teeth than to single ones. 



LINGUAL ERUPTION. 



713 



The earliest cases requiring treatment are of Class 1, and often pre- 
sent as early as the age of six or seven years, and before the tooth has 
fully erupted. If an upper central has erupted inside the normal line 
so as to bite inside of the line of the lower incisors when it is not more 
than half erupted, the case demands immediate treatment, because the 
farther the tooth erupts the greater will be its malposition, for it 
occludes on the inclined plane formed by the lingual surface of the 
lower incisor. 

One of the oldest appliances for moving a tooth forward or outward 
consists of a vulcanite plate with a piece of soft rubber or compressed 
wood attached to the edge so that it will press upon the malposed 



Fig. 637. 



Fig. 638. 




Plate with box, a ; b, rubber or compressed 
wood in box. 




Rubber tied on a plate 



tooth. The plate may be ligated firmly to the deciduous molars. The 
soft rubber may be held in a box cut in the edge of the plate (Fig. 



Fig. 639. 




Plate with gutta-percha extension. 



637), and increased in thickness as the tooth advances, or a piece about 
^g of an inch thick may be ligated to the edge by silk passing through 
holes near by (Fig. 638). As the tooth moves forward the plate may 



714 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



Fig. 640. 




be built out at this point by gutta-percha filled into a box cut in the 
edge and pressed against the tooth while still soft. The rubber may be 
ligated on the outer edge of the gutta-percha, which may be increased 
in amount at each visit (Fig. 639). 

The inclined plane, as illustrated in Fig. 640, may be made in 
various forms. It is one of the oldest forms of 
regulating appliances, and one of the most inef- 
ficient. It depends for its success wholly on the 
co-operation of the patient. With young patients 
its use is not as successful as with older. The 
principle is, that biting on the inclined plane 
slides the tooth forward, but soon the biting produces inflammation in 
the pericemental membrane, a " soreness " of the tooth as popularly 
expressed, when every bite causes pain and the patient naturally refrains 
from biting. It is efficient only with older patients who exhibit a de- 
termination to help the operation. The most efficient appliance is one 
which does not depend on the will of the patient for its action. 

Fig. 641 shows a very efficient appliance used by Dr. Mattesom 

Fig. 641. 



Inclined plane. 




"Tube, band, and spring" appliance (Matteson). 

With young patients he prefers " to band the first deciduous and first 
permanent molars, and joining these bands by a connecting strip on the 
buccal surface and a piece of metal tubing closed at one end on the 
palatal surface." A piece of piano wire is inserted in the tube and the 
free end allowed to press against the tooth to be moved. It is best kept 
in place by a band cemented on the tooth with a lug or half-section of 
tubing soldered to its lingual surface. 

If the band is made as recommended by Prof. Angle, by drawing 
the band material around the tooth with a pair of pliers and soldering 
together the projecting ends, this projecting portion may be left long 
enough so that a notch may be cut in it for the piano wire to rest in. 

In many cases of the age under consideration the second deciduous 
molar alone will be firm enough to be banded for anchorage. With 



LINGUAL ERUPTION. 



715 




an older patient whose teeth are more firmly set, a bicuspid or first 

molar alone will often be sufficient 

for anchorage. Fig. 642. 

For short teeth, such as decidu- 
ous molars or partially erupted 
bicuspids or molars, Dr. Matte- 
son uses swaged caps, made with 
Mellotte's moldine and fusible 
allov, so as to fit over the whole 
crown and be cemented in place. 
Two or more teeth may be in- 
cluded in one cap, and tubes may 
be soldered on either side for the 
attachment of springs, etc. (See 
Fig. 627.) 

A similar use of the piano-wire spring, but retained by the Jack- 
son crib, is shown in Fig. 642. Fig. 647 shows a different form of 
crib. Both Matteson's and Jackson's appliances are applicable to any 
of the six anterior teeth. 

A jack-screw with the flattened end resting in a slot in a band 
cemented on the tooth to be moved and the other end soldered to a 





Crib and band (Jackson). 



Fig. 643. 




Angle's jack-screw. 

band on a second bicuspid or first molar for anchorage, or resting in a 
socket in said band, is very efficient for moving a tooth outward, but is 
more applicable to laterals and canines than centrals. (See Fig. 643.) 
Another plan of retention of the anchor end of the jack-screw is to 
slip the open end of the tube over a pin or lug projecting from the 



716 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



molar band. The lug may be easily made by properly shaping the 
projecting ends left after soldering the band. The teeth selected 
for anchorage should be as nearly as possible in line with the move- 
ment desired, and it is best in many cases to solder a bar on the lingual 
surface of the anchor band, so that it will rest on contiguous teeth and 
thus increase the power of resistance. 




albot's spring with bands. 

Fig. 644 shows Dr. Talbot's coiled spring, with one end inserted in 
a small socket soldered to an anchor band on a molar and the other in 
a socket on a band on the lateral. If the bands are thickened on one 



Fig. 645. 




Plate and coil spring for moving canine. 

side, holes may be punched for the reception of the ends of the spring. 
Piano wire may be anchored in a plate so as to force a tooth outward. 
(See Fig. 634.) 

In some cases the lower incisors impinge so closely upon the necks 
of the upper as to leave no room for appliances unless the bite is 
opened, which is seldom necessary. 



LINGUAL ERUPTION. 



Ill 



Plate Axchorage. — The canine is such a difficult tooth to move 
that very firm anchorage is necessary. A plate constructed so as to 
cover the crowns of the bicuspids and molars will anchor all the 
teeth together and give plenty of resistance to a spring inserted as 
in Fig. 645 and pressing against the tooth to be moved. The end 
of the spring may rest in a hole or socket in a band cemented to 
the tooth. 

Fig. 646 shows an appliance operating outside the arch. A band 



Fig. 646. 




Writer's appliance, close bite : baud and outside spring. 

cemented on the first molar with a tube on its buccal surface forms the 
anchorage. In this tube is inserted a piano wire, which is bent to con- 
form to the arch of the teeth and its free end inserted in a tube or hook 
on the labial surface of a band cemented on the tooth to be moved. 
It may be applied to any of the six anterior teeth. If applied to a 
central or lateral the wire may rest on the cuspid as a fulcrum, which 
gives it greater power. 

The Jackson crib may be used for anchorage instead of the band 
and tube, as shown in Fig. 647. 

A bicuspid is easily moved out into line by the appliance shown in 
Fig. 648. The screw, which passes through a bar about \ of an inch 
wide, soldered to a band on a convenient tooth, may be cut off as the 
tooth is moved out. The same appliance may be used as a retainer. 

The appliance shown in Fig. 649 is highly recommended by Dr. 
Talbot, and described by him as follows : It is made of German silver, 
which possesses all the requisite qualities. He has three thicknesses of 
it ready for use, Nos. 29, 31, and 32, U. S. gauge. Strips are cut -^ to 
-| of an inch wide accordingly as strength is required, and bent with 
small round-nosed pliers into the shape represented at a to fit the teeth. 
This is removed every day and with round-nosed pliers the ends are 



718 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

bent, and the spring shortened and forced to place upon the teeth. The 



Fig. 647. 



Fig. 648. 




Crib, spring, and band (Jackson). 



Bar, band, and screw. 



little spring acts in two directions — first, to carry the teeth laterally 
and thus provide room ; secondly, to draw the irregular teeth into 
position. In the hands of the writer this has been a very efficient 
appliance. 

Fig. 649. 




German-silver spring (Talbot). 

Making Room. — If the adjacent teeth overlap the one out of posi- 
tion it is best to make room before attempting to move it, because it 
cannot advance until room is made for it, and force spent on it will be 
of no avail unless the tooth acts as a wedge to force the others apart. 
A piece of compressed wood, one of the oldest forces used in ortho- 
dontia, can be used in many cases as shown at a, Fig. 650. Cut a piece 
of wood about a third larger than the space, compress it with pliers or 
the vise; and insert it with the grain parallel to the axis of the teeth. 
If the sides are made slightly concave, it will hold in place better. As 
the wood absorbs moisture it will swell and press the teeth apart. 



LINGUAL ERUPTION. 



719 



A better method of gaining room is to cement bands on the two 
adjacent teeth with tubes on the labial surfaces. In these tubes insert 
a Matteson spring, as shown in Fig. 651. As soon as sufficient room 




Fig. 651. 




lljuky^ 



Compressed wood fur making room. 



Matteson spring applied to bands. 



is gained, a straight wire may be inserted in the tubes across the space. 
A rubber band stretched over the malposed tooth from this wire will 
soon move it into place. 

Fig. 652 shows a very satisfactory modification of the above appli- 
ance, using intermittent force instead of constant. A screw with two 

Fig. 652. 




Writer's appliance for making room and moving tooth out. 

nuts on it, or one collar and one nut, is inserted in the tubes, and the 
nuts screwed against the tubes. If one of the nuts is turned two or 
three times a day, the teeth will soon be moved apart. The nuts will 
hold the teeth apart while a rubber band or ligature passed over the 
screw and the malposed tooth will soon draw it forward, or if the rubber 
band is applied while the contiguous teeth are being spread apart, the 
tooth will move forward as room is made for it. 

Retainer. — The best retainer for a single tooth moved forward 
consists of a Magill band with a round wire soldered on its labial sur- 
face. (See Fig. 653.) A round wire is better than a flat bar, because 



720 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



it rests on the tooth at one point only and there is less liability of food 
lodging under it, as illustrated in Fig. 654. 



Fig. 653. 



Fig. 654. 




Writer's retainer band and round 
wire. 



Round and flat contacts 
in regulating fixtures. 



When a band is to be used as part of an appliance for moving a 
tooth into place, as in Fig. 643, a tube can be soldered to its anterior 



Fig. 655. 




Providing in advance for retention (Angle) 



surface. After the tooth is moved into position this same band may 
be used as a retainer by passing a wire through the tube so that its 



Fig. 656. 



Fig. 657. 





Angle's retainer. 



Talbot's retainer. 



ends will rest on adjacent teeth. This wire can be fastened in the tube 
with cement. (See Figs. 655, 656, and 657.) 

Class 2. Labial Eruption : A Tooth Erupted Labially. — The sim- 
plest method of moving such a tooth backward is by a rubber band or 
ligature looped over one tooth on each side of the prominent one, and 
passing over its labial surface. (See Fig. 658.) Although this is effec- 
tive in simple cases there is the theoretical objection that the rubber 
band or ligature tends to draw the contiguous teeth toward the promi- 



LABIAL ERUPTION. 



721 



nent one and thus to impede the very movement desired. One practical 
objection is that the rubber band tends to rotate the teeth over which 
it is looped. The rubber band may be ligated to the second tooth on 
each side and passed under the first. 



Fig. 658. 




Rubber band and ligature. 

The next simplest method is the strip of elastic German silver as 
described by Dr. Talbot — just the reverse of that shown in Fig. 649. 

One of the oldest appliances and an excellent one is shown in Fig. 
659. It consists of a plate fitting the roof of the mouth, held by atmos- 




pheric pressure in contact with the lingual surfaces of the teeth except 
with that of the prominent one. A rubber band stretched over this 
tooth is attached to the plate at some point directly in line with the 
movement desired, and far enough from the tooth to give the desired 
amount of force. For attachment a hook may be vulcanized, or a hole 
drilled in the plate at an acute angle, and a wooden peg inserted, which 
is kept tight by swelling. Another simple way to attach the rubber 
band is to drill two holes through the plate and tie with thread. This 

46 



722 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



has one advantage, that the patient may be allowed to remove the plate 
for cleansing without danger of losing the rubber band. 

If the adjacent teeth need to be moved apart to make room, the 

rubber band may be fastened to the 
plate at two points, as shown by the 
dotted lines in Fig. 659, or farther 
apart, so as to press laterally as 
well as backward. 

The plate may be ligated to teeth 
on each side of the mouth to hold it 
more securely, and a silk or linen 
ligature may be substituted for the 
rubber band. 

Fig. 660 shows Dr. Talbot's plan of gaining room by means of a 
coiled spring with the ends resting on the teeth to be spread apart. 

The plate may be dispensed with by cementing a band, to which a 
hook has been soldered, on some tooth in line with the movement de- 
sired, and stretching a rubber band from the prominent tooth over this 
hook. The anchorage may be increased by a wire or bar soldered to the 
outside of the band so as to rest on contiguous teeth. (See Fig. 661.) 

Fig. 661. 




Talbot's spring with bands, for making room. 




Band and bar for anchorage; rubber band for drawing tooth in (Guilford). 

In order to apply the force in the proper direction in moving a cen- 
tral incisor, it may be necessary to use a tooth on each side of the mouth 
for anchorage, in which case it is better to extend a rubber band from 
each anchor tooth to a hook on the lingual surface of a band on the 
central. (See Fig. 662.) 

The occlusion may be such that the cutting edges of the lower in- 
cisors nearly or quite touch the necks of the upper or the gum, and 
thus prevent the use of any appliance on the lingual surfaces of the 
teeth without opening the bite, which it is best to avoid if possible. In 
such cases (see Fig. 663) cement a band on a bicuspid or first molar on 



LABIAL ERUPTION. 



723 



each side, with a tube on the buccal surface. Through these tubes 
around the arch, and in contact with the prominent tooth, extend a 



Fig. 662. 




Double anchorage for elastic traction. 



labial bow of stiff wire, No. 16 B. & S. gauge, screw-cut at the ends. 
Place nuts on the ends of the bow spring behind the tubes. By turn- 



Fig. 663. 




Labial bow for drawing tooth in. 



ing the nuts pressure is brought to bear on the prominent tooth. To 
prevent the wire sliding on the surface of the tooth, cement on it a 
band on which is soldered a lug or a half-section of tubing in which 
the wire can rest ; or use Angle's notched band. (See Fig. 771.) If 
elastic wire, such as platinum-gold or German-silver wire, drawn hard, 
is used, constant force can be applied, as, when the nuts are turned, the 
wire will be bent and in its tendency to straighten will press on the 
tooth. 

Fig. 664 shows an appliance which may be used with much satisfac- 
tion. In this case the first molar has been previously extracted. The 



724 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

line between the central incisors is to the right of the median line of the 
face. The bicuspids are to be pushed back and the incisors toward the left 
at the same time. The appliance works on the principle of two wedges 
drawn toward each other. On the canine is cemented a band with a 
short tube on its lingual surface. In this tube is placed one of Angle's 
short drag-screws, while the other passes through a strip of metal about 

Fig. 664. 




Writer's appliance for making room and drawing cuspid in. 

-J- of an inch wide which rests on the first bicuspid and the lateral. 
This strip is bent so as to form one wedge while the canine serves as 
another. The nut on the end of the screw draws the two wedges, that 
is, the canine and the strip, toward each other and spreads the lateral 
and bicuspid from one another. The strip is altered in form as the 
work progresses — always, however, retaining its wedge shape. The 
same appliance may be worn as a retainer after the canine is in 
place. 

Class 3. Rotated Teeth. — While attachment may be made to a 
tooth for rotating it by ligatures (a modification of the clove hitch) or 
by drilling pits in which are inserted screws or pins secured by cement, 
the first of these serves only a temporary purpose, and the second 
mutilates the tooth more than is warrantable except in extreme cases. 

For the incisors the best attachment is a Magill band not thicker 
than No. 36 B. & S. gauge, to which is soldered a hook, pin, or tube. 
For the canines a swaged cap is better, as it may be cemented more 
firmly in place. 

To rotate an incisor which overlaps the adjacent tooth, cement a 
band on the tooth with a hook on either the labial or the lingual surface. 
From this hook extend a rubber band or ligature to a vulcanite plate 
held by atmospheric pressure. Secure the rubber band to the plate by 
ligating through two holes. (See Fig. 665.) The plate should be cut 
away slightly as the tooth rotates. The point of the attachment to the 
plate will vary according to the direction of force needed. By attach- 
ing at C, Fig. 712, room may be gained by attaching the rubber band 
so that it will press against the adjacent tooth, over which the offending 
one may be lapped. 



ROTATED TEETH. 



725 



The plate may be dispensed with by attaching the rubber band to 

some other tooth for anchorage 
Fig. 665. (Fig. 666), or to a lingual bow 

as shown in Fig. 667. 




Fig. 666. 




Plate and band for rotating. 



Two Magill bands for rotating. 



Extra force may be gained in rotating by passing the rubber once 
around the tooth after attaching it to the hook, as a rope is wound 
around a windlass. 

If it be necessary to rotate a tooth outwardly, attach bands with 
tubes to any two convenient teeth such as canines or bicuspids ; extend 



Fig. 66 




Writer's lingual bow and hook band for rotation. 

a wire bow from one to the other, as in Fig. 668, and use this as a point 
of attachment for the rubber band. The ends of the bow are prevented 
from passing too far through the tubes by the bending in bayonet shape 
or by pinching the posterior ends of the tubes. If the canines are used 
for anchorage, solder the tubes vertically to the bands and bend the 
ends of the bow at right angles. 

Force may be applied to the tooth from two directions by making 
hooks on both sides of the band and extending a rubber band or ligature 
from one hook to a labial bow and from the other to the lingual bow, as 
shown in Fig. 669, A and B. 



726 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

Fig. 668. 




Labial bow and hook band for rotation. 



In many cases another tooth which needs rotating may be used for 
anchorage, and thus double rotation is accomplished, either in the same 



Fig. 669. 







A, Rubber band from lingual hook to labial bow ; B, from labial hook to lingual bow. 

or opposite directions. A study of the illustrations Figs. 670-673 
will show the student how the different movements are accomplished. 



Fig. 670. 



Fig. 671. 





Fig. 672. 



Fig. 673. 




mgjgim. 
Bandage for double rotation. 




ROTATED TEETH. 



727 



In many cases a tooth may be moved out of or into the normal line and 
rotated at the same time by applying the force to a hook on a band. 
Where a jack-screw is used it can be applied at the mesial or distal 
portion of the tooth as needed. (See Fig. 674.) 



Fig. 674. 



Fig. 676. 




Angle's jack-screw for moving tooth outward and 
rotating. 

Fig. 675 shows one of Prof. Angle's 
methods, which he describes as follows : 
Fig. 675. 




Angle's pinched wire for extension and rotation. 

" The tooth was banded and one of 

the pipes soldered to the mesio-lingual 

Fig. 677. 




Retainer. 



gle's pliers for pinching wire. 



angle of the band ; one end of a piece of wire of suitable length was 
inserted into this pipe and the other end secured in a pit formed in the 



728 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



enamel of the second deciduous molar. Force was exerted upon the 
tooth to be moved by occasionally pinching this wire with the regu- 
lating pliers (Fig. 676), two or three pinches being enough to lengthen 
the wire sufficiently to move the tooth as far as should be done at one 
sitting. 

" The simplest retainer is a band with a short piece of round wire 
soldered to it, so that it will impinge upon the adjacent tooth. It is 
necessary sometimes to fasten such a lug on each side of the band." 
(See Fig. 677.) 

When double rotation has been accomplished, the teeth may be 
retained by soldering the bands together at the points of contact. 

Angle's appliance for double rotation is easily understood from an 
examination of Figs. 678 and 679. The piano-wire spring should not 
be larger than No. 24 B. & S. gauge. 



Fig. 678. 



Fig. 679. 





Angle's appliance for double rotation. 



Although this appliance is very effective, two difficulties attend its 
use. Sometimes the spring fails to slide through the tubes as the teeth 



Fig. 680. 



Fig. 681. 





Guilford's lever for rotating. 



Angle's detachable lever for rotating. 



rotate and the teeth are spread slightly apart. This tendency can be 
obviated by tying a silk ligature from one tube to the other. 

Sometimes the distal surfaces of the teeth will turn forward, so that 
they will stand wholly out of the line of the other teeth. This can be 
prevented by soldering lugs on the lingual surfaces of the bands, to rest 
on the laterals. In some cases, as the centrals turn, these lugs will 
slide on the inclined plane formed by the lingual surfaces of the laterals 



EXTRUSION. 



729 



Fig. 682. 



and either push the laterals up in the socket or elongate the centrals. 
This may be prevented by bands on the laterals with a projection on 
-each, under which the lugs will rest and be prevented from moving. 

Another method of rotating is by means of a lever attached to a band 
on the tooth as shown in Fig. 680. The end of the lever is bent in the 
form of a hook, from which a rubber band passes over some convenient 
tooth. Prof. Angle has made the lever detachable (Fig. 681) by solder- 
ing a tube to the band and inserting in it a piece of piano wire. The 
other end of the wire is bent in the form of a hook and ligated to some 
-convenient tooth, or placed under a hook soldered to a band on such 
tooth. 

Fig. 682 shows Dr. Matteson's swaged cap on a deciduous molar, 
with a hook for this purpose. In 
using the lever special care must be 
taken not to let it rest on any tooth 
between the anchorage and the of- 
fending tooth, otherwise it will move 
the tooth out of line. 

Class 4. Extrusion, or a Tooth 
Extruded. — The simplest treatment 
for a tooth that is extruded is to 
grind it shorter. As grinding alters 
the natural shape of the tooth in 
proportion to its extent, other means 
are sometimes necessary. 

A tooth sometimes elongates, in 
regulating, by the carelessness of the patient or operator, or by unfore- 
seen complications. In such a case an immediate, even though tem- 
porary, appliance is necessary. Tie a ligature around the necks of the 
adjacent teeth with the knots between each and the offending tooth. 
Extend one end of each ligature lingually and one labially. (See Fig. 

Fig, 683. 




Matteson's swaged cap for anchorage. 




Writer's plan for reducing extruded teeth. 



683.) Tie the lingual ends together behind the long tooth, and in the 
same knot tie a slender rubber band. (See Fig. 684.) Tie the labial 



730 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



ends together in front of the long tooth. Next stretch the rubber band, 
from the lingual surface of the neck, over the cutting edge, and tie it 



Fig. 684. 



Fig. 685. 





Writer's plan for reducing extruded teeth. 

to the knot on the labial surface. (See Fig. 685.) The tooth is thus 
hung in a sling which will force it up into place. 

Another simple plan is that suggested by Dr. William Herbst for 
retaining a replanted tooth. It is shown in Fig. 687. It consists in 



Fig. 



Fig. 687. 





Herbst method of reduction and retention. 



cutting a short and narrow strip from a piece of rubber dam (Fig. 686) 
and perforating it in such a manner that when in position the crowns 
of two teeth on either side of the one affected will protrude through the 
openings while the elongated tooth will be partly covered and pressed 
upon by the intervening portion of the rubber. (See Fig. 687.) 



Fig. 688. 




Appliance for reducing extrusion. 

A better plan is to band one tooth on each side and connect the 
bands on both labial and lingual surfaces by a wire soldered to both 
bands, or resting in tubes soldered to the bands (Fig. 688), or soldered 
to one band and resting in a hook on the other. A twisted ligature or 
slender rubber band stretched from the lingual to the labial wire, over 
the cutting edge of the long tooth, will soon force it up. (See Fig. 689.) 
A small cap with a notch in it may be cemented to the end of the long 



PARTIAL ERUPTION. 



731 



tooth, to prevent the rubber band from slipping off. When the tooth is 
moved to its desired position it may be retained by substituting a small 



Fig. 689. 



Fig. 690. 





Writer's appliance for reducing extrusion. 



Details of appliance shown in Fig. 



platinum wire or silver suture wire for the rubber band, or three bands 
may be soldered together and cemented to the teeth. 

Class 5. Partial Eruption. — A tooth may need elevating because 
it has not fully erupted or because a piece has been broken from the 
cutting edge. If the short tooth is an incisor, proceed as follows : On 
the adjacent teeth cement bands or caps which are connected by a wire 
at or near the cutting edge. On the short tooth, as near the gum as 

Fig. 691. 




Writer's method of elevating. 

possible, cement a wide band which has a hook or pin on both labial 
and lingual surfaces. From one hook stretch a very slender rubber 
band or twisted ligature over the wire to the other hook. (See Fig. 691.) 
Less force is required for elevating a tooth than for any other move- 
ment, as a conical root is drawn from a conical socket, and care must 
be taken not to move the tooth too rapidly lest the pulp be ruptured 
at the apical foramen or the peridental membrane be ruptured. If 
the wire is soldered on the cutting edges of the caps, it will prevent 
the possibility of drawing the tooth too far. For retention substitute 
a small platinum or silver suture wire for the rubber band, or apply 
three bands soldered together. A broken tooth may be elevated by 
means of the same kind of appliance (see Fig. 692), and then the cut- 
ting edge ground to conform to the other teeth. 

For a partially erupted canine an excellent plan is that of Prof. 
Angle, shown in Fig. 693. 



732 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



Where the canine has not erupted far enough for cementing a band 
or swaged cap on it, a small hole may be drilled in the tooth, in which 



Fig. 692. 




Writer's method of elevating broken tooth. 

a small screw or pin is secured by cement. This may be afterward 
filled with gold, or with a piece of a small glass rod, as described by 
Prof. L. L. Dunbar. 1 

In some cases it is advantageous to use teeth of the lower jaw for 
anchorage, as shown in Fig. 694. 

The patient may remove the rubber band from the upper tooth while 
eating. As rubber bands are liable to be broken by a too sudden 

Fig. 693. Fig. 694. 




Angle's method of forcible eruption. 



Angle's method of using the lower jaw for 
anchorage. 



opening of the patient's mouth, it is well to attach two or three to the 
lower tooth, as a reserve in case one is broken between visits of the 
patient. The lower metal band may be dispensed with by ligating the 
rubber band to the neck of the tooth. As the rubber band tends to 
draw the ligature away from the gum, inflammation is not likely to 
ensue as in many other uses of such a ligature. 

Figs. 695 and 696 show how this plan has been successfully applied 
by the writer for elevating bicuspids and molars which do not occlude. 
Bands with hooks are attached to both upper and lower teeth and a 
rubber band stretched from each upper hook to a corresponding lower 
one, or the place of either upper or lower band is supplied by a liga- 

1 Pacific Coast Dentist, vol. i. p. 14. 



PARTIAL ERUPTION. 



733 



ture. The teeth, being drawn out of their sockets toward each other, 
will soon meet and adapt their occlusal surfaces to each other. This 



Fig. 695. 




Writer's plan of occluding bicuspids and molars. 



adaptation may be assisted by grinding or re-shaping any cusps that 
may be an obstruction. The case shown in Fig. 696 was treated in 




Restoration of occlusion. 



the infirmary of the Dental Department of the University of Califor- 
nia by a senior student under the writer's directions. An unexpected 
result was also obtained. The upper arch was much narrower than the 



Fig. 697. 




Labial bow for elevating centrals and depressing canines. 

lower. The upper teeth were drawn outward as well as downward and 
the arch was widened. 

The following case will serve to illustrate reciprocal movement : 



734 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

The central incisors of a patient about twenty years of age were par- 
tially denuded of enamel for about T ^- of an inch from the cutting edge. 
The lateral incisors had the same defect at the cutting edge only. It 
was thought best to elevate the central incisors, and grind off the por- 
tion denuded of enamel. Bands were fitted to the centrals (Fig. 697) 
with hooks on their labial surfaces pointing upward, also on the canines 

Fig. 698. 







Labial bow for retention. 

with hooks pointing downward, and on the second bicuspids with tubes 
on their buccal surfaces. A wire bow was extended from the tube on 
the left bicuspid to the tube on the right, and caught under the hooks 
on the canines. Slender rubber bands were then stretched from the 
wire over the hooks on the centrals, and soon elevated them sufficiently 
to grind off the denuded portion. The same appliance was used as a 
retainer by bending the bow wire upward slightly and hooking it over 
the hooks on the incisors. 

The elevation of a broken upper incisor is sometimes interfered 
with by occlusion of the lower incisors on the slanting lingual surface 

Fie. 699. 




Flattening lower arch with labial bow. 

so that it is necessary to shorten the lower incisors by grinding. In 
some cases it is warrantable to grind away the upper incisor on the 
lingual surface, where too much grinding of the lower teeth would mar 
their appearance. In the case just described it was necessary to press 
the lower incisors back by flattening the arch as shown in Fig. 699. 
The following case of forcible eruption may be instructive : 
Miss R. W., aged eighteen, presented herself with the point of the 



PARTIAL ERUPTION. 735 

upper left canine erupting behind the lateral incisor while the deciduous 
canine was still in place. The cusp had penetrated the gum about a 

Fig. 700. 




Forcible eruption of canine. 

year before, but had during that time made no progress in eruption. 
The w r riter decided to cause the tooth to erupt forcibly, by means of a 
coiled spring as suggested by Dr. Talbot. As the deciduous canine was 
large and firm and but slightly decayed, it was thought best to let it 
remain in place till the permanent tooth was erupted far enough to see 
if it were well formed. By depressing the gum slightly a hole was 



Showing result of operation. 



drilled in the enamel in the lingual surface of the tooth. In this hole 
was inserted one end of a coiled spring, which was attached to a plate, 
as shown in Fig. 700, which shows the cusp emerging from the gum. 
The tooth was soon erupted to its normal length, when the deciduous 



736 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



canine was extracted. By means of a rubber band from a labial bow, 
the ends of which rested in tubes attached to bands on right and left 
bicuspids, the tooth was readily brought into line as shown in Fig. 701 , 



Fig. 702. 



Fig. 703. 





A band-and-bar retainer (Fig. 653) was applied to keep the tooth in 
place till it became firm. 

Tooth Shaping. — The operation of grinding has been referred to 
in the shortening of an extruded tooth, and also for re-shaping a tooth 
from which a corner has been broken after having first elevated the 
tooth. (See Fig. 692.) It may be advantageously employed for re- 
shaping teeth which have been left longer than the contiguous ones by 
the wearing away of the latter, as shown in Figs. 702-705, suggested 
by Dr. W. S. How. 1 

In many instances upper incisors are worn away on their lingual 
surfaces, leaving thin edges of labial enamel which are easily broken 
away irregularly. (See Fig. 706.) These broken edges may be re- 
moved and the teeth improved very much in appearance by grinding. 

The cusps of bicuspids and molars sometimes interfere with the 



Fig. 704. 



Fig. 705. 



Fig. 706. 





lljlli 



Worn or broken teeth (Farrar). 

desired movement of an antagonizing tooth and may be reduced by 
grinding so as to present no obstruction. 

Lower canines which prevent upper canines or lateral incisors from 
moving into their proper position may have the apex of the cusp ground 
away, and in some cases even a portion of the labial enamel may be re- 
moved to advantage. An incisor which inclines toward the contiguous 
tooth so much as to present one angle lower than the other may have 
this corner ground away so as to present the cutting edge in line with 
the other teeth. Fig. 707 shows how much of the enamel of a tooth 
may be removed in various cases without exposing the dentin. 
1 Dental Cosmos, vol. xxviii. p. 741. 



PARTIAL ERUPTION. 



737 



" Truing up " is a term applied by Dr. Farrar to the process of 
removing overlapping portions of teeth so that they will present a nor- 
mal appearance. (See Figs. 708 and 709.) 

Much discomfort may be prevented if the corundum wheel be 
held as in Fig. 710, as the tooth is supported by the contiguous ones 

Fig. 707. 




Showing thickness of enamel (Farrar). 

and less jar is felt. Fine-grained wheels should be used and the sur- 
face should afterward be thoroughly polished by means of cuttlefish 
disks, or with felt or wooden wheels carrying polishing powder. If 
the grinding should not be carried so far as to be painful a slight sensi- 
tiveness may be felt for a few days, when the operation may be resumed. 
Cataphoresis has been successfully applied by the writer for allaying 
sensitiveness. If a tooth needs to be reduced considerably in length 




Truing up (Farrar). 



the dentin may be exposed on the cutting edge with impunity, as it 
is kept free from decay by the tongue and lips. The enamel may be 
beveled on one or both surfaces to reduce the thickness of the cutting 
edge. 

Approximal Surfaces. — In rare instances the removal of a slight 
amount of enamel from approximal surfaces of incisors or canines is 

47 



738 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



permissible for the purpose of making room, 
confined to teeth easily kept clean, to 
teeth unusually rounded on their ap- 
proximal surfaces, and they should be 
reduced only to a normal contour and 

Fig. 709. 



The operation should be 




Fig. 710. 




Truing up (Farrar). 



Position of corundum wheel (Farrar). 



be thoroughly polished. Flat approximal surfaces should never be 
produced, as caries is almost sure to be the result. The patient should 
be warned to use extra care with the brush and floss silk. 

Disks or strips of sandpaper, emery, or garnet may be used for 
removing a portion of enamel, after which cuttlefish disks or strips 
should be used for polishing. 

Class 6. Two or More Teeth in Any or All of the Five Mal- 
positions. — One of the oldest and simplest appliances, which requires 
very little skill in its construction, is shown in Fig. 711. It can be 

Fig. 711. 




Labial bow and plate. (From Kingsley.) 

used with either upper or lower jaw, and consists of a vulcanite plate 
fitted against the lingual surfaces of the teeth. Imbedded in this plate 
are the ends of a wire which extends through such gaps, when the jaws 
are closed, as are most favorable, and around the buccal and lingual 
surfaces of the teeth. A round wire is much better than a flat strip of 
plate for this bow, as it can be bent up toward the gum line or down 
toward the cutting edges of the incisors according to the necessities of 



SEVERAL TEETH IN MALPOSITION. 739 

the case. The cut shows the manner of attaching rubber bands by 
which teeth may be drawn forward. The bow should be from -^ to ■§• 
of an inch in advance of the teeth to be moved, and may be elongated 
from time to time by hammering the sides on the beak of an anvil. 
By attaching rubber bands or twisted ligatures to the plate, teeth may 
be drawn into the arch, as shown in Fig. 712, B. By stretching rubber 
bands or twisted ligatures from either the wire or plate to hooks such 
as shown in Fig. 712, A, teeth may be rotated. For such purpose it 
is in some cases best to solder hooks on both labial and lingual surfaces 
of a band, and thus apply force from wire and plate at the same time. 
By attaching a rubber band at that part of the wire which emerges 
from the plate (Fig. 712), a tooth may be drawn backward along the 
ridge. If the wire extends near to the cutting edge, an incisor may be 

Fig. 712. 




Plate and wire bow for moving teeth in all positions. 

extruded by ligating a rubber band at the neck and extending it to the 
bow, or by applying a twisted ligature in the same manner. In some 
cases it is necessary to ligate the plate firmly to temporary molars or 
bicuspids. This has a wider range of use than any other single appli- 
ance, for with it teeth may be moved outward or inward, rotated or 
elongated, or the arch may be spread. (See Fig. 712, A, B y C, D.) 
It is, however, much less stable and much more uncleanly than are 
many other appliances attached directly to the teeth. 

The same movements may be made with the bows shown in Fig. 713. 
Bands are cemented on one or two teeth on each side of the mouth, pre- 
ferably two for stability, in which case the bands should be soldered 
together. Tubes are soldered on both buccal and lingual sides of the 
bands. In these tubes are inserted wire bows, screw-cut on the ends 
and supplied with nuts. One bow extends around the labial and the 
other around the lingual surfaces of the teeth. 



740 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



To these wire bows, rubber bands may be attached to move teeth in 
all directions, for instance at B y for moving a lateral incisor into the 
arch ; at A, for rotating a central incisor ; at D, for drawing a canine 
backward along the ridge; and at C, for drawing a lateral forward. 



Fig. 713. 




Labial and lingual bows for teeth in all positions. 



This last rubber band should not be applied till after the canine has 
been moved out of the way. 

This appliance, made up of labial and lingual bows, has as wide a 
range of application as the plate and bow, and is much more stable as 



Fig. 714. 




Appliance for rotating several teeth at one time. 



well as much more cleanly. Fig. 714 shows the use of this appliance 
for rotating several teeth at one time. 

The bows may be used independently as follows : The labial bow may 



SEVERAL TEETH IN MALPOSITION. 



741 



be used for moving incisors backward by placing the nuts behind the 
tubes (Fig. 663), or for moving incisors forward by placing the nuts in 
front of the tubes and ligating the wire to the incisors, or putting it 



Fig. 715. 




Labial and lingual bow. 

under hooks soldered to bands on the incisors. It may be used for the 
attachment of rubber bands or twisted ligatures for drawing incisors for- 
ward (Fig. 729), in which case the wire may be bent in a bayonet shape 
at the ends, or the rear ends of the tubes may be closed. 



Fig. 716. 




Lingual bow for moving incisors forward (Matteson). 

The lingual bow may be used for moving any or all four incisors 
forward by placing the nuts in front of the tubes. The anterior portion 
of the wire may rest in notches in the bands on the incisors (Fig. 716), 



742 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



Fig. 717. 



or a short piece of wire may be soldered to the front of the bow and 
inserted between the centrals above the points and their mesial sur- 
faces. Other short wires may be soldered on so as to engage the distal 
borders of the laterals to prevent their being moved sideways. (See 

Fig. 715, b.) 

Fig. 717 shows the writer's modi- 
fication of the Coffin spring plate for 
moving incisors forward. A wire 
should be imbedded in the anterior 
portion of the plate to project between 
the centrals to prevent sliding on the 
inclined surfaces. 

Eetention of Teeth Moved 
Forward. — This has often been ac- 
complished by a simple vulcanite 
plate retained by atmospheric pressure 
and impinging on the lingual surfaces 
of all the teeth involved. Objections 
to this are that it is easily displaced, 
even sometimes by the incisors on whose inclined surfaces it impinges ; 
retention of fermenting debris or secretions in contact with the teeth, 
and liability to be left out by the carelessness of the patient, when the 
teeth return partly to their malpositions. Fig. 718 shows a retaining 




Writer's modification of Coffin split vul 
canite plate. 



Fig. 718. 




E.H.A. 

Angle's retainer. 

appliance of Prof. Angle's, consisting of a wire bent so as to rest in 
contact with the lingual surfaces of the teeth involved, soldered to 
bands on the canines, and the ends cemented in pits drilled in the 
molars. It may be used in the lower arch as well as the upper. In 
many cases the anterior portion only of this appliance may be used. 



RETAINING PLUGS. 



743 



Several teeth moved in different positions may be retained by bands 
soldered together and cemented in place. (See Fig. 719.) 

Fig. 720 shows Dr. Case's retainer, 1 which consists of a series of 
bands soldered together at their points of contact with an excess of 



Fig. 719. 



Fig. 720. 





Bands soldered together for retention. 



Case's retainer. 



Fig. 721. 




Swaged strip for strengthening. 



solder in front. The labial surfaces of all but the end bands are then 
cut away so as to leave only a small portion between the teeth, and 
these portions filed so as to resemble gold fillings. The appliance is 
stiffened by soldering a piece of swaged plate to the lingual surfaces. 
(See Fig. 721.) The bands should be constructed of very thin gold- 
faced platinum or German silver, prefer- 
ably the former, and the whole appliance 
firmly cemented to the teeth. 

Retaining Plugs. — It not infre- 
quently happens that on account of the 
crowded and irregular positions of teeth, 
cavities of decay have been formed which 
can be used, as suggested by Dr. Farrar, for the insertion of gold 
retaining plugs or fillings. For instance, approximal fillings may be 
inserted in an incisor and built out so as to touch the contiguous teeth 
for retaining a tooth ; or a tooth that has been moved into line may be 
retained by gold fillings inserted in approximal cavities and built out 
laterally so as to rest on the labial or lingual surfaces of contiguous 
teeth ; or a tooth that has been rotated may be retained by one such 
filling. 

This method of retention is especially useful with patients who have 
advanced beyond the years in which it is generally considered advisable 
to regulate teeth. The writer had a patient forty-five years old for 
whom he moved two teeth forward into line. After an immovable 
retaining appliance had remained in place for over two years the teeth 
upon being released moved back perceptibly. Gold fillings were inserted 
in approximal cavities and built out as suggested above, with the inten- 
tion of leaving them indefinitely. 

Care should be taken to make these projections as slender as the 
1 Ohio Dental Journal, January 1898, vol. xvii. No. 1. 



744 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

strength of the gold will permit, so that the point of contact with the 
enamel will be as small as possible. 

Lower Incisors Crowded in All Positions. — This is a very common 
irregularity owing to the teeth being too large for the incisor space, or 
the space being encroached upon by the canines. 

The simplest way to make room is to extract one of the crowded 
teeth. The four teeth are so nearly of the same size that few can tell 
without counting whether there are three or four between the canines. 

When room has been made, the remaining teeth may be brought into 
line by the same means that have been described for upper incisors. 
The labial bow attached to bands on bicuspids or canines will form 
attachment for rubber bands or ligatures for moving the incisors into 
position. In some cases it is better to spread the arch as shown in Fig. 
733. Owing to the relative positions of the alveoli of the central incisor 
and canine to that of the lateral incisor there is always a tendency for 
the lateral incisor to erupt within the arch of the adjoining teeth. 

In selecting the tooth for extraction in such cases it would seem most 
natural to take the one most out of position labially or lingually ; but 

Fig. 722. 




that is not always best, because it often happens, as Dr. Case has 
shown, that the contiguous teeth already lean toward each other, and 
if drawn together after removal of such teeth will only lean toward 
each other all the more noticeably with quite a V-shaped space at the 
gum. 

If possible, the tooth for extraction should be so selected that the 
contiguous teeth lean from each other (Fig. 722), so that when drawn 
together they will be forced into an upright position. If, however, a 
wrong selection should have been made, the roots of the contiguous 
teeth may be forced toward each other by the appliance shown in Fig. 
821. 1 

Caution. — Before deciding on extraction in such cases the operator 
should satisfy himself that the lower arch does not need expanding to 
make room for the crowded incisors. 

If by removing a tooth the lower arch is allowed to contract and the 

1 Dr. Case, Dental Review, 1898, p. 584. 



PROMINENT CANINES AND DEPRESSED LATERALS. 745 

bicuspids move nearer the median line, their cusps may by wedging con- 
tract the upper arch and cause crowding of the upper incisors. Fig. 
733 shows an appliance for expanding the lower arch. 

Class 7. Prominent Canines and Depressed Laterals. — Etiology. 
This common form of irregularity may be due to — 

(a) Lack of development of the intermaxillary bone — constitutional. 

(6) Teeth too large for the jaw — indirect heredity : teeth from one 
parent and jaw from the other. (See page 690.) 

(c) Premature loss of the deciduous second molars and forward move- 
ment of the permanent first molars — acquired. 

(d) Premature loss of the deciduous canines — acquired. 
(Figs. 605, 723, and 725 illustrate irregularities under Class 7.) 
Treatment — To make room for proper arrangement of the teeth in 

this class, it is necessary either to expand the arch or to extract one or 
more teeth. 

If the irregularity is slight, and the arch is narrower than the oc- 
cluding one, expansion is indicated. 

If both arches are narrow, both should be expanded to restore proper 
occlusion. 

Unless the arch will admit of expansion to advantage, extraction is 
better. 

If expansion would make the arch too large, or the anterior teeth 
too prominent, extract. 

If the superior maxilla itself is so narrow that expansion would 
make the bicuspids and molars slant outward too much, extract. 

If caries is prevalent, extract. 

In favor of expansion, it may be said that if the full number of teeth 
are retained, the pain of extraction is obviated, and the narrow arch is 
widened to correspond with the other features. 

In favor of extraction : Room is gained more easily ; the treatment 
is simplified, as there are fewer teeth to be moved ; the teeth are retained 
in their new positions more easily, because if the full number of teeth 
be retained the same cause that produced the irregularity may tend to 
reproduce it, while if room be made by extraction the action of the lips 
and tongue tends to move the teeth into the normal arch. 

In many cases no other treatment than extraction is necessary, as 
shown in Figs. 723 and 724. 

Having decided upon extraction in any case under consideration, the 
choice lies between a lateral incisor and some tooth posterior to the 
cuspid. The canine should never be extracted, as on account of its 
long root and prominent position its loss causes a depression of the 
corners of the lip and wing of the nose which can never be remedied. 

The choice between a lateral incisor and some tooth posterior to the 



746 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



canine depends on the position of the apex of the root of the canine, 
and also of the lateral. If the apex of the root of the canine is so 

Fig. 723. 




Case treated by extraction only. 



situated that the crown slants away from the median line, or will do so 
after being moved into its normal position, the extraction of one or both 
laterals may be admissible. If a lateral is unusually far back of the 
normal line and the apex of the root also, when the tooth is moved 

Fig. 724. 




Showing the same denture as Fig. 723 a few months after extraction. 

forward till the cutting edge is in line with the centrals the neck of 
the tooth will be back of its proper position — that is, the tooth will 
have an unnatural slant forward. This is not of as much importance as 
the position of the apices of the roots of the canines, but it should be 
taken into consideration in connection with the other factors. 



PROMINENT CANINES AND DEPRESSED LATERALS. 



747 



One method of moving incisor roots is shown in Figs. 823-827. 

In very rare cases a central incisor may be extracted to gain room — 
that is, if very badly decayed, if an incurable abscess exist, or if only 
the root remain and cannot be crowned to advantage. 

In the lower arch an incisor may be extracted to advantage in many 
cases ; the four teeth are so nearly alike in appearance that the absence 
of one is not noticed. 

If in a given case it seems best to extract some tooth posterior to 
the canine, the choice will be between a bicuspid and the first molar. 
If the bicuspids and first molar be equally sound, extract the first 
bicuspid. That will leave two teeth for anchorage in retracting a 
canine (Fig. 725, left), or, if the second molar be erupted far enough, 




Writer's modification of Guilford's appliance. 

three teeth may be utilized. Very secure anchorage is necessary in 
this instance, for the canine is the most difficult tooth to move, and 
oftentimes the two anchor teeth will move more readily than the canine. 
In some cases the canine needs to be moved back but little ; then the 
second bicuspid only need be used for anchorage (Fig. 725, right), and 
the two teeth moved toward each other to fill up the space. The molar 
will follow, owing to the tendency of the posterior teeth to move 
forward. This forward movement or migration of molars is very 
curious, and is often a very great hindrance in regulating, since they offer 
less resistance as anchor teeth from that very cause. Fig. 728 shows 
a case in which a molar has moved so as to touch the canine, yet still 
retains its upright position. The upper molar in migration has less 
tendency to tip forward than the lower. If, however, the second bicuspid 
or first molar be so defective as not to be preserved by filling, the defect- 
ive tooth should be extracted. This, however, will complicate the case, 
as there are more teeth to be moved and fewer for anchorage. On 
account of the value of the molar in masticating and in preserving 
normal occlusion, it should not be extracted unless caries has advanced 



748 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



so far that there is a doubt whether the tooth can be saved by filling or 
crowning. (See page 744 on extraction.) 

In using the appliance shown in Fig. 725 rubber bands are gener- 
ally utilized for applying force, but twisted ligatures of silk, linen, or 

wire may be used, as shown 
in Figs. 726 and 727, in which 
case there is less liability to 
pericemental inflammation. 

Fig. 727. 



Fig. 726. 





(Same as Fig. 725, but with wire.) 



Twisted ligatures of silk, linen, or wire. 



Tubes are soldered on the buccal surfaces of the bicuspid or molar 
bands and shaped so as to serve for hooks. They are afterward utilized 
for holding a labial bow (Fig. 729). 

After the canine is moved into position, it may be retained by sub- 
stituting fine platinum or silver suture wire for the rubber bands. The 



Fig. 728. 




Showing migration of molars. Eight first molar in contact with first bicuspid, and 
left touching the canine. 

buccal tubes, which served as hooks in the first case (see Fig. 726), may 
now be utilized for inserting the ends of a wire bow which passes in 
front of the incisors. Eubber bands or twisted ligatures from this bow 
will draw the lateral incisors forward. (See Fig. 729.) An inner bow 
may be placed in the lingual tubes and utilized for drawing central 



PROMINENT CANINES AND DEPRESSED LATERALS. 



749 



incisors backward, or rotating them, as is often necessary in such 

cases. 

Fig. 729. 




Fig 



Labial bow added to retracting appliance. 

If either canine needs rotating, a rubber band will be needed on 
one side of the tooth only, and 
the hook may be so placed on 
the band that the tooth will be 
rotated while it is being drawn 
back. 

Prof. Angle advises the use 

Fig. 730. 





Stationary anchorage (Angle). 



Angle's drag-screw. 



of the drag-screw for retracting canines, as shown in Fig. 730. By 
soldering a long tube to two bands which are cemented to two teeth, 
and extending the drag-screw through this tube, he reduces to a mini- 
mum the possibility of the teeth tilting. This appliance is very 
effective. The position in which the hook is attached to the canine 
band will depend on whether it should be rotated or not in retraction. 
(See Fig. 731.) 

After the canines are moved to their new position the same appli- 
ance may remain as a retainer. It will be found that a canine moved 
into its proper place, when room has been made by extraction, will need 
retention less than any other tooth. 

Greater anchorage may be obtained by a plate such as shown in 
Fig. 732, for it impinges upon the anterior alveolar ridge and in- 



750 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

cisors as well as upon the posterior teeth. Its use is especially ad- 
vantageous when a second bicuspid or first molar has been extracted, 
for then one or two teeth must be moved before the canine. The cut 
will explain the method of applying force to the teeth to be moved. 
The wire or clasp should encircle the posterior tooth, for greater anchor- 
age. After the second bicuspid has been drawn back, the first can be 
moved in the same manner ; then the canine. In many cases it will 

Fig. 732. 




Plate for retraction. 

be best to move the canine by the reciprocal appliance shown in Fig. 
733, so as to relieve the anchor teeth from undue strain. 

It is to be clearly understood that the condition shown in Fig. 732 
must be one of necessity, not of choice. 

The molar is so important in masticating and in preserving the normal 
relation and interlocking of cusps of occluding teeth that it should not 
be removed if it can be avoided. 

Present methods of crowning molars are so successful and perma- 
nent that in most cases crowning should be resorted to if the tooth is 
too far gone to be filled, even if a sound bicuspid must be removed to 
give room. 

Fig. 733 shows a reciprocal appliance for these cases by Dr. R. L. 
Taylor, of San Francisco. The laterals are drawn forward and the 
canines pushed back and elevated at the same time, after the first 
bicuspids have been extracted to make room. This has proved a valu- 
able appliance and is well adapted to such cases as are shown in Fig. 
732, after the bicuspids have been moved back. 

Fig. 734 shows a valuable appliance by Prof. Guilford for moving 
four incisors forward, and bicuspids back, to make room for canines. 
He thus describes it : " Magill bands were made to fit the laterals, with 
gold spurs extending along the palatal surface of the centrals to insure 
uniform movement of the four incisors. Palatal bands were also at- 
tached to the first bicuspids. All of these bands were reinforced with 



PROMINENT CANINES AND DEPRESSED LATERALS. 



751 



an additional piece of platinum soldered to the portion next to the 
space. Through these reinforcements, at about the centre of the tooth, 

Fig. 733. 




Dr. R. L. Taylor's reciprocal appliance. 



holes were drilled entirely through the bands. Piano wire was next 
bent into the form of small U-shaped springs, with the ends at right 
angles, similar to Dr. Talbot's plan but without the coil. Grasping 
these near the neck with a pair of narrow-beaked right-angle forceps, 



Fig. 734. 




Guilford's appliance for increasing space. 



transversely grooved near the points to seize the wire, the springs were 
placed in position with their ends resting in the holes in the bands. As 
from time to time the force of these springs became spent they were 
removed and their power renewed by enlarging their curves." 

In case of extraction of first molars, the bicuspids may be moved 
backward and the incisors forward by Prof. Guilford's appliance. 

Fig. 735 shows Prof. Angle's method of reinforcing the anchor 
teeth by a wire bar extending to the lateral incisor. 



752 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



In many cases, after extraction of a first bicuspid the only problem 

Fig. 735. 




Angle's reinforcement. 



is to draw the canine into line or move it lingually. This may be ac- 
complished by any of the appliances described in Class 2. 



Fig. 736. 

lYimiiiiiiiiiii 




Drawing canine in. 

Fig. 736 shows another method of Prof. Angle's for drawing the 

Fig. 737. 



canine in 




Jackson's appliance for lower arch. 

The lower canine is the most difficult tooth to move. If the first 
bicuspid be extracted to make room, the second bicuspid and first molar 
will in many cases be moved forward in an attempt to use them as 



PROMINENT CANINES AND DEPRESSED LATERALS. 



753 



anchorage in retracting the canine either with a screw or elastics. If 

a first molar has been lost, we have the sum of difficulties, — three teeth 

to move and only the second molar for anchorage. It is often neces- 

F , r;J8 sary to construct an appliance 

of such a shape that all the 
other teeth can be used as 
anchorage. 

Fig. 739. 




Jackson's appliance for lower arch. 



Flat tube for piano-wire spring. 



Figs. 737, 738 show Dr. Jackson's method of retracting the lower 
canine in such cases. The base wire rests against all teeth that it is 
not desired to move and gives effective anchorage. 

Fig. 739, A, shows another method of applying a piano-wire spring 
by bending a loop on one end and inserting it in a flat tube soldered 
to a molar band ; the spring is thus prevented from turning. The loop 

Fig. 740. 




: ! 

Stability of anchorage. 

may be so bent that the spring may be inserted in the posterior end of 
the flat tube, as shown at b, Fig. 739. 

" When great immobility of the anchorage tooth is required, use for 
banding material German silver or platinized gold, No. 30 gauge and 
as wide as the tooth will permit. When these are contoured and fitted, 
solder the power tube at the gingival margin. (See Fig. 740.) This 
should be sufficiently long to permit reinforcing it at either end with 
solder to the full width of the tooth, and large enough to carry a 
power rod that will be inflexible. Where it is possible, the power tube 
may rest above the gingival margin, soldered to an extension plate 
that is fitted or swaged to the surface of the crown, and so shaped as to 
freely clear the gum. 

48 



754 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



" If the power tube is extended forward to the first bicuspid and 
its anterior end allowed to rest upon a narrow projection soldered to 
the bicuspid band, it will add greatly to the stability of the anchorage. 

" It will be seen that any tendency of the molar to tip forward 
will carry the anterior end of the tube almost directly toward the 

Fig. 741. 




Author's combination for expansion. 



root of the bicuspid, the movement being prevented by the rest. Nor 
will any such device offer any special obstruction to the movement of 
the bicuspid, the rest sliding along the tube." 

The " power bar," or drag-screw, should end in a hook engaged in 
a tube on the canine or any other tooth that needs to be moved. 




Matteson caps in place of bands in appliance for expansion. 



Spreading the Arch.— For spreading the arch an appliance 
should be firmly fixed upon the teeth and should have sufficient power, 
which can be well regulated. For such an appliance the writer has 
made a combination of Magill bands, Angle's jack-screw, and the coil 



SPREADING THE ARCH. 



755 



spring, as shown in Fig. 
same purpose, it has this 
the lingual surfaces of 
holes in which are fitted 
screw. This bar should 
position of the screw or 
which needs the greater 



741. While resembling other devices for the 
distinction : The bar connecting the bands on 
the teeth is perforated at short intervals by 
the ends of a Talbot spring or an Angle jack- 
be stiff, about ]S T o. 23 B. & S. gauge. The 
spring may be changed, according to the part 
expansion. If necessary, two springs or two 




Writer's combination with Angle's jack-screw 



jack-screws may be used at the same time. The coiled spring should 
be bent to conform to the palatal vault, so as to interfere but little 
with the patient's tongue as does the jack-screw. 

In case of very short molars and bicuspids it is best to use Matte- 
son caps in place of bands, as shown in Fig. 742. 

Fig. 744. 




Writer's appliance for widening lower arch and moving incisors forward. 

Fig. 743 shows the use of the jack-screw and Fig. 744 the appliance 
for the lower arch. In this the Matteson spring is used with two coils 



756 



0RTH0D0N1IA AS AN OPERATIVE PROCEDURE. 



between which is a straight part Avhich lies near the floor of the 
mouth. 

When the arch has been spread the bent wire c, Fig. 741, is sub- 
stituted for the spring or jack-screw for retention. It may lie along 
the necks of the teeth, and in such position be utilized for attachment 
of rubber bands for retracting or rotating incisors, as shown in Figs. 
667 and 713. The long wire a, 6, Fig. 741, is used for moving incisors 
forward, as shown in Fig. 729. These two wires are the labial and 
lingual bows previously referred to. 

Fig. 745 shows one of the author's " partly made " appliances, 
which can be readily applied to the teeth of a patient or to a plaster 

Fig. 745. 




Partly made appliance for expansion. 



cast by bending the partly made bands around the teeth and completing 
them as in Fig. 630. 



Fig. 746. 




Partly made expander applied to plaster cast. 



The perforated bar soldered to the first band ribbon slides through a 
flat tube on the second band ribbon, and thus allows adjustment accord- 
ing to the amount of room desired between the bands. Fig. 746 shows 
the completion of the appliance. 



THE POINTED OR GOTHIC ARCH. 



757 



Class 8. The Pointed or Gothic Arch (the V-shaped Arch) 
(called the Lancet Arch by Dr. Guilford). — Etiology. — The pointed 
arch (generally miscalled the V-shaped arch) may be due — 

(a) To the presence of teeth too large for the jaw — indirect heredity; or 

(b) To the first permanent molar having moved forward from its 
normal position on account of premature loss of the second deciduous 
molar — acquired. 

In either case, taking the first molar as a fixed point for the base of 
the arch on each side, the teeth forward of that point must arrange 
themselves in a portion of the jaw which is too small for them. The 
incisors erupt first, the bicuspids next, and the canines last. It depends 
on the manner of approximal contact whether the result is a pointed 
arch, a constricted arch, or results in Class 7 — " Prominent canines and 
depressed laterals/' 

If all of these teeth erupt in proper alignment, they will touch each 
other approximally like the stones of an arch ; the second bicuspid not 




Pointed arch (V-shaped arch). 



having sufficient room — either from its extra size or because the first 
molar has taken part of its room — will crowd the first forward, and the 
canine, erupting as a wedge in front of the bicuspids, which are immov- 
ably fixed against the first molar, will crowd the incisors forward, 
because they are situated in a thin alveolar process which is easily 
moved. As the incisors move forward, crowding upon each other, they 
rotate in their sockets and assume the V shape. 1 

(c) The teeth may assume a pointed arch from having too much 
room, either on account of extraction or from being too small for the jaw. 
When the teeth are deprived of approximal support there is a tendency 
for the sides of the arch to flatten or move toward the median line. 
1 See Talbot, 3d ed., chap, xxxii., and Ottolengui, Dental Cosmos, June 1892. 



758 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



The semi-V of Dr. Talbot's classification is one in which the causes 
named have operated on one side only of the arch. Fig. 748 shows a 

semi-V arch due to the last cause 
mentioned. 

(d) The V shape assumed by 
the central incisors may be due to 
lack of development of the inter- 

Fig. 749. 





Semi-V-shaped arch. 



Apices of roots too near together. 



maxillary bone at the median suture. This would bring the apices of 
the roots of these teeth nearer each other than is normal. As the teeth 
erupt they may come in contact with each other above the gum line, but 
be separated from each other at the mesio-incisal angles. If they are 
now crowded together by the lateral incisors, or if an attempt be made 
to draw them together by means of a rubber band or ligatures, they will 
roll upon each other in such a manner that when the mesio-incisal 
angles touch they have also assumed a V shape with the apex of the 
V pointing forward. 

Conversely, when a V shape of this kind is reduced by double rota- 
tion, 1 the teeth will assume the position shown in Fig. 749. 

The old theory that it was due to mouth-breathing is no longer ten- 
able, as it has been demonstrated that the pressure of the muscles upon 
the teeth in such action is not sufficient to cause this deformity. This 
has been proved by examination of a great number of children in schools 
and public institutions. 

Treatment — The treatment of the pointed arch depends on the 
relation in size between the jaw and teeth. If the teeth are not too 
large for the jaw, and the deformity consists in the flattening of the 
sides of the arch, the operation is comparatively simple. If pressure 
be brought to bear on the summit or point of the arch while the base on 
each side is fixed, the sides will spring outward like an arch of whale- 
bone. (See Fig. 750.) 

Many pointed arches are also cases of upper protrusion, and will be 
treated of under that division. 

One of the oldest appliances and a very satisfactory one is shown in 

1 See Class 3. 



THE POINTED OR GOTHIC ARCH 759 

Fig. 751. The posterior teeth should be partially surrounded by the 

Fig. 750. 




Angle's appliance for spreading arch and reducing V shape. 

plate, or by wire or clasps imbedded in the plate, to give firm anchor- 
age. The rubber bands attached to the T-piece between the central 
incisors should be attached to the edges of the plate as shown, in order 
to apply the force in a direct line with the movement desired. 




Plate for reducing V arch (Kingsley). 

Bands and a labial bow (Fig. 759) may be used, in which case the 
bands should be applied to the posterior teeth. The bow should be of 
elastic wire, not smaller than No. 16, and so shaped as to press on the 
centrals only at first. As these teeth move back and press on the late- 
rals, and these in turn on the canines, and so on, the arch will spread 
out and can thus be moulded to the shape that has been given to the 
bow. This may be assisted by rubber bands from the bow over the 
bicuspids and canines. 



760 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



In some cases the arch must be spread before attempting to reduce 
the V shape, in which case the appliance shown in Fig. 741 may be used. 

Fig. 752 shows the second stage in the treatment of a pointed arch. 
The arch is first spread by means of a coil spring acting on a band 



Fig. 752. 




Writer's lingual bow and rubber bands for rotation after spreading the arch. 

on the first bicuspids, reinforced by bars resting on the canines and 
second bicuspids. After sufficient room has been gained the lingual 
bow may be inserted to retain the width of the arch. From this bow 
a rubber band or a twisted ligature should be extended to a T-piece 
between the central incisors or to a hook on a band on each central 
incisor for the purpose of rotating. 

Fig. 753. 




Upper protrusion— cause (a) or (b). 

Class 9. Upper Protrusion. — Etiology. — Protrusion of the upper 
anterior teeth may be due to several causes : 

(a) Abnormal (excessive) development of the upper maxilla — con- 
stitutional. 

(6) Teeth too large for the jaw — indirect heredity. 

(c) Premature loss of the second deciduous molar, and forward move- 
ment of the first permanent molar — acquired. 



UPPER PROTRUSION. 



761 



(d) Thumb-sucking — acquired. (See Fig. 757.) 

(e) Lack of development of the lower maxilla (the upper protrusion 
is then apparent rather than real) — constitutional. 



Fig. 754. 




Protrusion— cause (c) (Talbot). 



(/) Premature loss or injudicious extraction of the first permanent 
molars — acquired. Prof. Guilford says of such extraction : " The re- 
sult is that the lateral pressure so necessary to proper expansion is lack- 
ing in one jaw while in the other normal enlargement continues." 



Fig. 



Fig. 756. 





Apparent protrusion due to lack of develop- 
ment of lower maxilla (Talbot). 



Dr. Louis Jack's drawing (in Dental Cosmos) 
showing deformity from too early extrac- 
tion of first permanent molar. 



(g) Weak structure of the upper maxilla, which allows the teeth to 
be forced forward by occlusion with a large lower maxilla of hard and 
dense structure with short rami — acquired. (See Fig. 757.) 



762 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



(h) It may be due to extraction of the lower first molars at an age 
when they were the only masticating teeth, as might be the case during 
an interval between the loss of the deciduous molars and the eruption 
of the bicuspids. The impaction of the lower incisors upon the inclined 
lingual surfaces of the upper incisors might move them forward, thus 
causing upper protrusion. (See Fig. 756.) 

Thumb-sucking. — To this practice were formerly ascribed all cases of 
upper protrusion, until inquiries developed the knowledge that in a 

Fig. 757. 




Upper protrusion— cause (d), from thumb-sucking. (Talbot.) 



majority of cases no such habit had existed, or, if so, had been aban- 
doned before the eruption of the permanent teeth. The fact that the 
habit of thumb-sucking, which usually begins before the temporary 
teeth are erupted, is indulged in during the years when the bony parts 
are especially soft and yielding and is discontinued before the eruption 
of the permanent teeth, and that nevertheless upper protrusion rarely 
occurs with the deciduous teeth, has completely overthrown the old 
theory. Yet thumb-sucking is occasionally persisted in till twenty- 
eight permanent teeth are erupted, and occasionally causes protrusion. 
Dr. Ottolengui says : l "It seems to me that if it is ever true at all 
that thumb-sucking can cause a protrusion of the jaw, we have it within 
our means to determine when such a condition has so resulted. If a 
given case of protrusion is attributable to thumb-sucking, it must of 
necessity follow that had the child not practiced the habit the jaw 
would not have protruded. Admitting this, then, we come to this — 
that the protrusion has occurred in one of two ways : First, the length 
of the arch around the circle has not been enlarged, but the projection 
has been produced by a flattening of the sides — pointed arch. The teeth 
1 Dental Cosmos, 1892, vol. xxxiv. p. 447. 



UPPER PROTRUSION. 



763 



being normal, but simply distorted, it must follow that such a case could 
be restored without extracting any teeth, or in plainer language, that by 
widening the jaw and reducing the forward prominence we may obtain a 
normal mouth with all the teeth in proper position. The second class of 
cases is where the length around the arch is increased, thus accounting for 




Pointed arch. 



Protrusion with spaces. Protrusion — teeth too large. 

Labial bow for three cases of protrusion. 



the anterior prominence. In such a case the pressure would be supposed 
to have moved the teeth forward, new tissue forming the Avhile. The 
result would be a normal occlusion from the bicuspid region backward, 
but a protrusion forward, with a distinct spacing between the teeth. 
This of course would be another condition which could be corrected 
without the loss of a tooth." 

Fig. 759. 




Labial bow for reducing upper protrusion. 

Treatment. — The treatment of upper protrusion will be considered 
under four heads : 

A. Where there is a flattening of the sides of the arch (pointed arch). 

B. Where there are spaces between the teeth. 

C. Where a tooth must be sacrificed on each side to make room. 



764 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



D. Where there is not sufficient anchorage inside the mouth. 

The first three classes may be treated in the same manner, by means 
of the labial bow shown in Fig. 759. The bow should be of stiff 
elastic wire, not smaller than No. 16, which will retain its shape, and 
should be bent at first into the exact form desired for the arch in the 
finished case, and should be prevented from sliding toward the gum 
by notched bands on central incisors. 

In class A (pointed arch) it will press on the central incisors only, 
and cause the flattened sides of the arch to spread outward. If they 
do not readily do so, rubber bands may be extended from the sides 
of the bow over any teeth desired. 

In most cases the greatest possible stability of anchorage is neces- 
sary ; then bands for the bicuspid ; and both should be soldered to- 
gether (Fig. 760, «). Such bands should be made of No. 30 band 

Fig. 760. 




Increased anchorage. 

ribbon as wide as the crown will allow. Fig. 629, E, shows the double 
band partly constructed. 

In many cases the second molar is too short for a band, but some- 
times a stiff wire may be extended back from the first molar band so as 
to hook around the second molar, perhaps extending slightly under the 
gum or pressing it away (Fig. 760, 6). 

In class B the teeth will be drawn toward each other and the spaces 
closed ; and in class C if the first bicuspids are extracted the six anterior 
teeth will be drawn back till the canines occupy the vacant spaces. If 
these six teeth were in the curve of the normal arch they will be moved 
back in the same position. If some are more prominent than others, 
the more prominent ones will be drawn back first and all moulded into 
the desired alignment. 



UPPER PROTRUSION. 



765 



The tooth to be extracted will depend or the same rules as in Class 
7 — " Prominent canines and depressed laterals." 

In some cases the upper protrusion is slight, so that the anterior 
teeth do not need to be moved back more than half the space left by 




Guilford's appliance for retracting upper incisors. 

the first bicuspids. Then it is an advantage to have the posterior teeth 
— the anchor teeth — move forward half the distance and fill up the gap, 
unless that plan would disarrange the occlusion, in which case the 




^ ,,,',■,,.'>■■■■■ '' - ■ ■■•■■■' " : \ III 

Labial bow and plate (Kingsley). 

bicuspid only may be moved forward so as to divide the space. The 
cusps of the upper bicuspid and the occluding teeth may in some cases 
be advantageously ground so as to improve the occlusion. 

Fig. 782 shows Prof. Angle's appliance for reducing the lower arch, 
which can be applied also to the upper. By a careful examination it 
will be seen to be practically a labial bow made up in three sections. 



768 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



In obstinate cases it would be the best appliance, for sometimes with 
the bow the teeth crowd together and tend to overlap. This is impos- 
sible with Angle's appliance, for all the force is applied to the canines, 
which in turn draw the incisors along: with them. 



Fig. 763. 




Jackson's method. 

The anterior teeth may be moved back by means of a plate and 
elastic bands such as shown in Fig. 761. The plate should be well 
secured by clasps around the molars. 

Fig. 762 shows Dr. Kingsley's plate with a labial bow of stiff wire, 
the elasticity of which is depended upon for moving the anterior teeth. 
At each visit of the patient the ends of the bow are bent so as to re- 

Fig. 765. 





Case of upper protrusion. 



Result of treatment with cap and bit. 



new the pressure. This is an excellent appliance for reducing a pointed 
arch. 

It is sometimes advisable to retract the canines first, by some of the 
methods described in Class 5, and then the incisors by the plan just 
mentioned. 



UPPER PROTRUSION. 



6" 



Fig. 763 shows the use of piano wire after the method of Dr. 
Jackson, which explains itself. The springs attached to the vulcanite 
plate or to the Jackson base wire and crib " following around from each 
side of the labial surfaces of the canines and incisors, pass each other at 
the median line " and press like long fingers. 

For moving back the roots of the teeth after the crowns have been 
moved, see page 796. 

Class D may include any of the others. The anchorage may be 
insufficient for the first two classes on account of the loss of posterior 
teeth from caries. In class C the teeth to be moved may exceed in 

Fig. 766. 




Writer's form of cap and bit for retraction. 

number the anchor teeth so that the latter will move instead of the 
anterior teeth. Fio;s. 764 and 765 show such a case. In such in- 



Fig. 




The bit. 



stances it is necessary to use the back of the head for anchorage. 
The first recorded instance of such use was by Dr. Norman W. 
Kingsley in 1865. 

Various complicated appliances for attachment to the anterior teeth 
have been described by different authors. Fig. 766 shows a very simple 



768 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



one first used by the author in 1880. It consists of a vulcanite cap fit- 
ting the labial and part of the lingual surfaces of the anterior teeth (Fig. 
767). In this is imbedded a steel or German-silver wire, about No. 12, 
so that the ends will protrude between the lips at the corners of the 
mouth. These ends are bent into hooks, and extended far enough so 
that elastics from them to the cap on the back of the head will not touch 
the cheeks. These extended arms may be bent to conform to the curve 
of the cheeks, but should not touch them. The cloth cap is such as any 
seamstress can make easily, and extends forward above and below the 
ear. On these projecting ends are sewed dress-hooks. For power use 
round or flat elastic cord. Tie a knot in one end, place it in the hook 

Fig. 768. 




Ten teeth moved at once. Condition before treatment. 



Fig. 769. 




Same denture after treatment. 



above the ear, extend it forward over the hook of the " bit " and back 
to the hook on the cap below the ear, and tie a knot in it to secure it. 
In most cases two or more strands will be needed ; if so, extend the 



UPPER PROTRUSION. 



'69 



cord forward again over the hook on the bit, and back again to the 
upper or to the lower hook. By thus varying the number of strands 
from the hook above or below the ear, the movement may be made 
directly backward from the cutting edges, or upward and backward 
somewhat in the line of the roots, in which case the teeth will be forced 
up into the sockets, or shortened. The ends of the wire passing out 
of the corners of the mouth may be adjusted by bending upward 
to just the right degree, so that the pressure of the "bit" will not be 
on the cutting edges, but at the necks of the teeth, or even higher, so 
as to move the roots and process also. To insure this, the vulcanite 
portion of the "bit" should pass over the cutting edge so as to grasp 
the lingual surface. 

This cap-and-bit appliance may be worn at night only, or at such 
other times as will not prevent the patient from attending school. The 
movement will be facilitated if a retaining appliance be worn during 
such times as the cap is not in use. The posterior teeth will often 
afford sufficient anchorage for retention. 

This appliance is especially valuable in cases in which it is necessary 
to select for extraction second bicuspids or first molars on account of 
caries, for then the number of teeth for anchorage is decreased and the 
number to be moved is increased. 

Figs. 768 and 769 show a case in which ten teeth were moved at 
once, by this appliance. 

Fig. 770. 




Angle's appliance for retraction. 



During the daytime, when the cap is not worn, the teeth may be 
retained by the labial bow shown in Fig. 759, which explains itself. 

49 



770 ORTHODONTIA AS :AN .OPERATIVE, PROCEDURE. 

The nuts should be turned in the inorriing "'only enough to retain but, 
not to move the teeth. 

If the upper protrusion is complicated with other irregularities, such 
as a pointed arch, or single teeth in any of the first five positions, Prof. 
Angle's appliance shown in Figs. 770, 771 will be found very satisfac- 
tory. The labial bow is held in position by bands on the central in- 
cisors, having notches formed in the united ends on the labial surfaces, 
c, c. The ends slide through tubes on molar bands. From the front 
of the bow projects a short wire ending in a ball on which is adjusted 
the socket of the traction bar, A. From the ends of this traction bar 
rubber bands extend to a cap on the back of the head, as shown 
in Fig. 772. As this wire bow is moved backward by the external 

Fig. 772. 




Angle's cap. 

force, it will move the teeth with which it comes in contact and mould 
the arch to the shape of the bow ; or, if single teeth need special move- 
ments such as rotation, elevation, etc., it may be accomplished by means 
shown in Fig. 713. Dr. Angle advocates the use of wire ligatures 
with the bow for various movements of the teeth, as shown in Fig. 
773. The rubber bands shown on the sides of the bow are for retain- 
ing the teeth during the day, while the cap is not worn. 

For retention, nothing is better than the labial bow, as shown in 
Fig. 759 ; but Dr. Case's retainer (Fig. 720) is much less conspicu- 
ous. The anchor bands may be placed on the second bicuspids or first 
molars, or on both. 

" Jumping the Bite." — Many cases of apparent upper protrusion 
are due to lack of development of the lower maxilla, so that the lower 
teeth close one cusp back of the normal position and the lower second 



"JUMPING THE BITE." 771 

bicuspid closes behind the upper second instead of in front of it, which 
is the normal articulation. Fig. 774 shows such a case of disto- 
lingual occlusion. 

Fig. 773. 




E.H.A. 

Wire ligatures with the bow, for various movements of the teeth'. 

If the lower jaw can be moved forward the width of a bicuspid, or 
less, sometimes, the normal occlusion will be produced. This move- 
ment is termed " jumping the bite,' 7 and originated with Dr. N. W. 
Kingsley more than twenty years ago. 

The lower jaw may be voluntarily moved forward but not backward. 
Any patient with an abnormal occlusion can move the lower jaw for- 

Fig. 774. 




Disto-lingual occlusion. 

ward the width of a tooth and thus occlude normally. If this can be 
made a permanent habit, the patient will have " jumped the bite." 

Unless some change takes place in the glenoid cavity, such as a filling 
up of its posterior portion, or in the condyle, such as the bending of the 
neck, as suggested by Dr. Case, or in the angle of the jaw itself, so as 
to prevent the jaw from moving back into its old position, the new 
position cannot be maintained. 

The first recorded operation of this kind was described as follows 



772 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



by Dr. Kingsley : 1 " Fig. 775 shows another application of the in- 
clined plane somewhat out of the ordinary course. It was adapted 
to the inside of the upper dental arch, and the inclined surface pro- 
jected below and caught the lower incisors. The object was, not to 
protrude the lower teeth, but to change or jump the bite in the case of 
an excessively retreating lower jaw. In the engraving is shown a 

Fig. 775. 




Kingsley's appliance for "jumping the bite." 

gold bar worn across the front of the upper incisors to reduce their 
prominence." 

Figs. 776, 777 illustrate a case treated by Dr. E. H. Cutter of Cam- 
bridge, Mass., and show the bite jumped half the width of a bicuspid. 
He says : 2 " I made a plate for the upper arch .... thickened only 
behind the front teeth where depressions were made to receive the 

Fig. 776. 




Cutter's case of "jumping the bite." 

points of the lower incisors .... and held firmly in place by wire 

clasps encircling the first molars I made several plates of this 

character, as the amount to be gained had to be gradually accomplished. 

The patient was twelve years old, and but one permanent second molar 

had erupted ; when the work was completed all four of these molars 

1 Oral Deformities, p. 84. 2 International Dental Journal, vol. xv. p. 355. 



LOWER PROTRUSION. 



773 



had erupted and interlocked with each other. The result was that the 
patient could comfortably bring her jaws together only as they had been 
newly related." 

Dr. Talbot says : l I have never been able to jump the bite .... 
Were such a thing possible, one of two things must take place. First, 
absorption and deposition of bone cells at the weakest part of the jaw ; 

Fig. 777. 




Cutter's case after adjustment. 

namely at the angle .... Second, there must be a forward movement, 
by absorption, of the condyle in the glenoid cavity." 

Fig. 778 shows Prof. Angle's method of "jumping the bite" by 
means of a spur imbedded in the lower permanent molar, thus com- 
pelling the normal closure of the jaw. 

Fig. 778. 



V 






Angle's method of "jumping the bite." 

Class 10. Lower Protrusion. — Etiology. — This irregularity is in 
most cases constitutional and may be attributable to the following 
causes : 

(a) Excessive development of the ramus of the lower maxilla, as 
shown in Fig. 780 — constitutional. 

(b) Excessive development of the body of the lower maxilla, as 
shown in Fig. 781 — constitutional. 

(c) The habit of finger-sucking, in which the finger is hooked over 
the lower teeth — acquired. 

1 Dental Cosmos, vol. xxxiv. p. 791. 



774 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

(d) Teeth too large for the jaw and therefore projecting forward of 
their natural position— indirect heredity. 

(e) The lower protrusion may be apparent and not real, owing to 
lack of development of the upper maxilla. This may be due to nasal 

Fig. 779. 




Lower protrusion (Talbot). 

obstruction (page 697) or to the injudicious extraction of the first per- 
manent molars, as in cases of apparent upper protrusion — acquired. 

(/) It may result from the upper oral teeth having erupted back 
of their proper position, so as to bite inside of the lower incisors. 

(g) Mal-occlusion of incisors. 

Fig. 780. 




Excessive development of ramus (Talbot). 



Treatment — If the teeth are too large for the jaw, room may be made 
by extraction of the first bicuspids, unless teeth posterior to them are 
selected on account of caries. 

The anterior teeth may be moved back by the labial bow shown in 



LO WER PROTR USION. 



775 



Fig. 759. Teeth as far back as possible should be selected for anchor- 
age. The anterior portion of the bow should be as near the cutting 
edges of the incisors as the occlusion will allow and may be prevented 
from sliding toward the gum by one or more small hooks over the cut- 
ting edges of the teeth or by bands on incisors or canines with lugs or 
notches. (See Angle's notches in retracting appliance, Fig. 771, o, c.) 
Dr. C. S. Case utilizes the upper teeth for anchorage. The labial 
bow previously referred to is applied to the lower teeth and has a 
button attached to it near the canine on each side. From this button 
a rubber band is extended to a similar button soldered to a band on 
an upper molar, as far back as possible. The tendency of this is to 

Ftg. 781. 




Excessive development of body of lower maxilla (Talbot). 

draw the upper teeth forward, but more especially to draw back the 
anterior lower teeth and also the jaw itself. 

Fig. 782 shows Prof. Angle's appliance for this purpose — " the large 



Fig. 782. 




Angle's appliance. 



traction screw being attached to clamp bands which encircle the first 
lower molars and the angles of which are hooked into small staples 



776 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



soldered to bands upon the distal angles of the canines/ while a piece of 
gold wire attached by solder connects these bands and passes in front 
of the incisors." This cap and traction bar may be used in connection 
with this appliance by applying the latter to the projection in front. 



Fig. 783. 




Allan's appliance. 

While more complicated than the appliance shown in Fig. 760, it must 
be very efficient. 

Constant force may be used by such an appliance as is shown in 
Figs. 762 or 763. The form of plate should be modified for the lower 
arch. 

When the posterior teeth do not give sufficient anchorage, an exter- 
nal appliance must be resorted to. The cap and bit shown in Fig. 766 
may be applied to the lower teeth, or Angle's appliance (Fig. 770) may 
be used if the six anterior teeth are not in proper alignment in respect 
to each other. 

If the protrusion is an example of true prognathism — that is, due 
to the lower maxilla being larger or longer than the upper from either 
of the causes mentioned — external force alone can be of use. 

By a cup of metal swaged to fit the chin and connected by rubber 
bands with a cap on the back of the head, as shown in Fig. 783 or in 
Fig. 784, the protrusion may be reduced. 

How this is accomplished is a matter of dispute, some maintaining 
that the lower maxilla is bent at the angle and others that the condyle 
is pushed back in the glenoid cavity. Dr. G. S. Allan said in 1878, 



LOWER PROTRUSION. 777 

" The jaw at that period of life is completely developed and hardened 
.... consequently any efforts that may be made will not affect the 
jaw-bone itself. The only way in which the change can be made is by 
pushing the jaw back into the glenoid cavity. . . . Absorption takes 
place at the posterior side of the condyles, with filling in of the ante- 
rior." Prof. Angle says, " The object is by continued pressure to bend 

Fig. 784. 




Angle's chin retractor. 

the jaw at the angles, but only in very young patients do we believe 
this even possible. We think that in two cases we have succeeded." 

Cases sometimes occur in which the fault is in both jaws ; the upper 
jaw is not prominent enough while the lower is too prominent, and the 
result is lower protrusion. Fig. 788 shows such a case, in which 
the fault lies partly in the spaces between the lower bicuspids and the 
first molar. The appliance was made after a similar one by Dr. Case. 
It consists of bands on the lower canines joined by a wire that encircles 
the incisors and the ends of which are bent into hooks. On the upper 
first molars are cemented bands with buccal hooks. A strong rubber 
band was extended from the hook on the lower canine to the hook on 
the upper molar band. The result is shown in the second cast (Fig. 
789). The patient was lost sight of after that. Just what changes 
took place is uncertain, — whether the movement was wholly of the 
lower teeth or whether there was a forward movement of the upper 
teeth also. The writer is inclined to the latter opinion. 

When the prognathism is apparent and not real — (e) and (/) — the 
proper treatment is to move the upper incisors forward, and in some 
cases the canines also. (For appliances adapted to this purpose see 
Figs. 716 and 717, in Class 6.) 



778 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



In some, lower protrusion from this cause is apparent only when 
the patient masticates. Figs. 785 and 786 will illustrate this condition. 



Fig. 785. 



Fig. 786. 




Apparent lower protrusion— during mastication. 



The patient's natural occlusion. 



If the upper incisors erupt slightly back of their proper position the 
cutting edges will occlude with the cutting edges of the lower incisors. 
As eruption continues they will open the bite (Fig. 786) so that the 
patient must throw the lower jaw forward in order to occlude the bicus- 



Fig. 787. 




The same denture after treatment. 

pids and molars. (See Fig. 785.) It is quite possible that this will 
result in a permanent protrusion of the lower jaw. The case shown in 
Figs. 785 and 786 was an argument against that, however, and against 
-the possibility of "jumping the bite " (see page 770), for the patient 
-was thirty years old, and never protruded his lower jaw except when 
masticating. For many years mastication had been attended with 
neuralgia in the temporo-maxillary articulation, caused by the unnatural 
strain, yet this neuralgia disappeared entirely after the upper incisors 
and canines had been moved forward enough to close in front of the 
lower. The teeth were moved by the split plate shown in Fig. 717. 

In moving forward the upper anterior teeth in cases of " apparent 
lower protrusion," such as shown in Fig. 785, or those due to lack of 
development of the upper maxilla, it sometimes occurs that when the 
cutting edges overlap the lower incisors the crowns have a very 
unnatural slant forward, and the roots need to be moved forward. 



LOWER PRO TR USION. 



779 



At the World's Columbian Dental Congress in 1893, Dr. C. S, Case 
presented casts and appliances for this operation, which are shown in 
Chapter XXV., Figs. 839, 842, 893, and 895. 



Fig. 7 




Lower protrusion (fault in both jaws). 
Fig. 789. 




Result of reciprocal appliance. 

By this means the entire anterior plate of the alveolar process is 
moved forward with the roots of the teeth and the sunken lip restored 
to its natural fulness. 

See facial contour in Figs. 840 and 843. 

Surgical Treatment of Lower Protrusion. — The following extracts are 
from a description, by Dr. J. W. Whipple of St. Louis, of the case 
shown in Fig. 790. 

There had been apparently an abnormal growth of the body of the 
maxilla between the first and second bicuspids on the left side and be- 
tween the first molar and second bicuspid on the right side, the space 
separating these teeth being respectively one-quarter and one-eighth of 
an inch, causing the elongation of the jaw horizontally, which projected 
the lower teeth a quarter of an inch beyond and in front of the upper 
ones. The occlusion was destroyed. This elongation, Dr. Whipple 



780 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



states/ had taken place between 1891 and 1896, the patient being 
eighteen years of age when he first saw him. Dr. Whipple advised the 
patient " to consult Dr. E. H. Angle, who first suggested the advisabil- 
ity of resorting to double resection in this case." About a year after- 
ward an operation was performed, and about a quarter of an inch was 
removed from the body of the bone on each side, Dr. V. P. Blair 
being operator-in-chief. 

" An incision was made about half an inch in length along the base 
of and just interior to the lower border of the maxilla. A cross incision 
was made of the same length, about on a line with the mental foramen. 
The centre of these incisions was interior, upon the borders of the 
neck. The muscles and other integuments were now detached from the 

Fig. 790. 







Lower protrusion. (Dr. Whipple's case. 



jaw-bone. Dr. Blair had devised or had constructed a double bone- 
saw, consisting of two saws, four inches long, attached to a single handle, 
and so adjusted as to make a cut in the clear just as wide as the space 
between the two bicuspids on the left side. The sawing was done 
through the incision from and through the internal surface of the bone 
from the upper border down to the base. No vessels were ligated, as 
the hemorrhage was not profuse after the vessels emptied themselves. 
The bone was cut almost, but not quite, through. No attention was 
given to the inferior dental canal. 

" A small hole was now drilled through the bone on each side of the 
cut, near the lower border, for the reception of a wire ligature. 

" The second right bicuspid having been previously extracted, the 
operation just described was repeated on the right side. 

1 Dental Cosmos, 1898, vol. xl. p. 552. 



LOWER PROTRUSION. 781 

" After the holes were drilled the remainder of the sawing was done 
on both sides, and the two small sections of the jaw removed. 

u Soft copper wire ligatures were now passed through the holes from 
the external surface. These were crossed on the internal surface, grasped 
with a pair of pliers, and twisted until the several* parts were drawn 
together at the lower border, forming an apparently close and smooth 
abutment of the opposing ends. 

" The copper wire ligatures proved ineffectual, so clamp bands, 
with buccal tubes, were applied to the molar and bicuspid on one side, 
and to the molar and canine on the other, and traction screws ex- 
tended through the tubes. By tightening the nuts on these screws the 
parts of the jaws were brought again in contact. As an additional pre- 
caution, ' bicuspid fracture bands ' were placed on the first upper and 
second lower bicuspid. 

Fig. 791. 



Result of surgical treatment of lower protrusion. (Dr. Whipple's case.) 

" A figure-8 ligature of brass wire was adjusted to the little knobs 
on these bands, and the rear fragment was firmly ligated to the upper 
jaw. All the various parts were held absolutely without change for 
five weeks. The patient lived on liquid food and suffered no great in- 
convenience physically. 

"A four- tailed plaster bandage was adjusted and retained without 
change for four weeks/' 

Within eight or nine weeks the appliances were removed from both 
sides, osseous union having taken place. Subsequently some of the 
posterior teeth were lengthened by means of gold crowns, and the 
occlusion restored. The final result is shown in Fig. 791. 

There was " an entire loss of sensation in the lower lip, caused by 
cutting the sensory parts of the inferior dental nerve. 

" The pulps of the middle part of the jaw do not seem to have been 
affected at all. 



782 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

" The gentleman's appearance is greatly improved. No one would 
suspect that such an operation had been performed." 

Dr. Angle suggests ] that in such cases the chin is usually very promi- 
nent, so that there is more or less lingual inclination of the lower incisors 
and that the section of bone removed should be wedge-shaped, wider at 
the lower border, instead of with parallel sides. 

He also suggests that the best way to hold the parts of the jaw in 
place would be to make a cap or splint of metal or vulcanite that would 
fit over the crowns of the teeth and cement it in place, as is done in 
the fractures. To properly construct such a cap or spliut, plaster models 
should be made of both upper and lower jaws, then sections cut out of 
the lower one so that the teeth could be properly adjusted to the upper, 

Fig. 792. 




Vulcanite or metal splint. 

taking careful measurements of the parts. On this reconstructed model 
a vulcanite or metal splint should be formed, as shown in Fig. 792. 
After the sections of the jaw are removed and the anterior portion forced 
back in contact with the remainder, the splint can be cemented on the 
teeth to hold the parts firmly in correct position. 

Class 11. Double Protrusion, or Protrusion of Both Upper and 
Lower Teeth.— Occasionally there is protrusion of both upper and 
lower teeth on account of their being too large for the jaws. The lips 
appear very much thickened, or are unable to cover the teeth. A case 
of this character (shown in Figs. 793 and 794) was treated by the writer, 
primarily with the cap and bit, such as are shown in Fig. 766, and 
secondarily by means of labial bows, shown in Fig. 795. The vulcanite 
bit was made to fit over the anterior part of the bows upon both upper 
1 Dental Cosmos, 1898, vol. xl. p. 635. 



DOUBLE PROTRUSION. 



783 



and lower incisors when the mouth was closed, and was worn except 
during school hours, the patient being a school-girl aged seventeen. 



Fig. 793 



Fig. 794. 




Double protrusion. (Corrected.) 

The bows, which were used only for retention, had their ends secured 
in tubes on bands cemented to the first molars. The anterior part of 
the upper bow rested in notched bands cemented on the central incisors. 
The anterior part of the lower bow was held in place by notched bands 
on the lower canines. The nuts of each bow were tightened every 

Fig. 795. 




Eetaining appliance. 

morning just enough to make up for the movement produced by the 
cap and bit during the night. There were thus utilized four anchor 
teeth in each jaw, the right and left first molars and second bicuspid. 
This was sufficient for retention of the six anterior teeth, though it 
would not have been sufficient for their retraction. If these anchor 
teeth moved forward it was not noticeable, for no space was left between 
the first and second molars, though that fact might be accounted for by 



784 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



a forward movement of the second molars of their own accord. Treat- 
ment of this case was begun in March, 1895, and in August the six 



Fig. 796. 



Fig. 797. 





Before. 



After. 



Double protrusion. 

anterior teeth had been moved back till the canine touched the second 
bicuspids. (Figs. 793 and 794.) 

The same bands and bows were worn about two months longer for 
retention, after which the teeth remained firmly fixed. The change in 
the contour of both lips was most marked. (See Figs. 796 and 797.) 

Fig. 798. 




Saddle-shaped arch. 

The relation of these cases of protrusion to facial contour is dis- 
cussed at length in Chapter XXV. 

Class 12. Constricted Arch (Saddle -shaped). — Etiology. — The 
constricted arch may be due primarily to the same cause as the pointed 
arch ; that is, (a) teeth too large for the jaw, or (b) the first permanent 
molar being forward of its natural position on account of premature loss 



CONSTRICTED ARCH. 785 

of the second deciduous molar, (c) Too long retention of deciduous 
molars, which may deflect the erupting bicuspid toward the median line. 
In either of the first two cases the position of the second bicuspid 
in eruption will determine the character of the arch. If it erupts in 
an exact line between the first bicuspid and the first molar it will crowd 
the anterior teeth forward (Fig. 799, B), but if it erupts to the slightest 
degree to one side of the direct line, it will itself be crowded out of the 
arch lingually or buccally (Fig. 799, A). The former occurs much more 

Fig. 799. 




Showing crowding of bicuspid or canine, or both, out of line (Ottolengui). 

frequently. When the canine erupts between the lateral and first bicus- 
pid in proper alignment it will gain space in the line of least resistance, 
and thus crowding the first bicuspid will force it back against the 
second, which in turn will be crowded still more inside the arch, thus 
producing the constricted arch. 

If the canine erupts before the bicuspids, it forms with the in- 
cisors a firm base and is not easily moved on account of its long root. 
The first bicuspid erupts next, and the second bicuspid, coming later, 
will, for want of room, be crowded inside the arch. The conditions 
may not be the same on both sides of the mouth. The crowding may be 
on one side only, producing the semi-saddle arch, or varying on the two 
sides may produce the semi-saddle on one side and on the other the 
semi-V, or the canine may be crowded entirely out of the arch (Class 7). 

Treatment. — The treatment of the constricted arch will depend upon 
whether the case is one of normal teeth and a small arch which will 
admit of enlarging, or whether the arch when spread would be too 
large for the other features. 

If the arch will admit of enlarging, it may be done by banding the 
teeth that are inside, and applying a jack-screw or Talbot spring be- 

50 



786 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



tween them, as shown in Fig. 741, thus forcing them outward till they 
are in proper alignment. 

In case of a semi-saddle-shaped arch (Figs. 609 and 610) — that is, 
one in which the irregularity is confined to one side — three or more 
teeth on the opposite side should be grouped together for anchorage. 

If the case is an aggravated one which will not admit of expansion, 
extraction must be resorted to — selecting, of course, the tooth or teeth 
most out of line. 

Class 13. Lack of Anterior Occlusion. — Etiology. — This irregu- 
larity is generally of constitutional origin, and may be due — 

(a) To lack of development of the ramus of the lower maxilla. 
(See Fig. 800.) 

(b) To lack of development of the anterior portion, or 

(c) To hypertrophy of the posterior portion of the alveolar process. 

(d) It may be acquired by thumb-sucking, as shown in Fig. 801. 

The jaws being held apart thus pre- 
vents normal eruption of the anterior 
teeth and consequent development of 



Fig. 801. 



Fig. 800. 




Lack of anterior occlusion (Talbot). 



Lack of anterior occlusion caused by thumb- 
sucking (Talbot). 



the anterior portion of the alveolar ridge, or allows excessive develop- 
ment of the posterior portions. 

(e) It may be acquired from the habit of mouth-breathing, which, 
relieving the molars from pressure, permits abnormal development of 
the alveolar process containing them. A case recently occurred in 
the writer's practice which illustrates this. The patient was fifteen 
years of age, and was a mouth-breather. There was a space of an 
eighth of an inch between the cutting edges of the upper and lower 
incisors, while three or four years before she could bite off a thread 
with these same incisors. 

That the opening was not caused solely by the eruption of the 
second molars was shown by the fact that the first molars occluded 
equally well. The case was reduced by grinding the molars till the 



LACK OF ANTERIOR OCCLUSION. 



787 



incisors touched, yet not enough of the teeth was removed to render 
them sensitive. Figs. 802 and 803 illustrate this case. 



Fig. 802. 




Lack of anterior occlusion. 



Lack of anterior occlusion is often accompanied, as shown in these 
figures, by other irregularities, which may be treated subsequently. 



Fig. 803. 




First bicuspid removed to make room for canine ; occlusal defect remedied by grinding. 

(/) Fig. 804 shows a case due to lack of development of the inter- 
maxillary bone. When nine years old both upper central incisors were 

Fig. 804. 




Lack of development of intermaxillary bone 



knocked out without fracturing the teeth or the process. The writer 
replanted the teeth after removing the pulps and filling the canals with 
gutta-percha. The teeth at that time were about two-thirds erupted, 
and did not erupt any farther. The growth of the process surrounding 



788 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

these teeth was arrested and that of the intermaxillary bone and ad- 
jacent part of the upper maxilla retarded as shown. The cast was 
made at the age of sixteen, at which time one of the teeth was still so 
firm as to permit the insertion of a gold filling, while the other was so 
loose from resorption of the root that it was extracted. The socket 
was deepened and enlarged and a tooth implanted. 

The influence of heredity may be prominent in this deformity, several 
members of one family presenting the condition. 

While this irregularity is generally of constitutional origin it is not 
always developed till the eruption of the second and third molars, or, if 
slight, while the first molar is the posterior tooth, is increased in de- 
gree by the eruption of the second and the third molars, just as a pair 
of dividers kept open a certain distance by a prop two inches from the 
joint will be opened farther if a prop of the same height be placed 
between the first one and the joint. 

The writer has been fortunate enough to be able to watch the devel- 
opment, in its later stages, of such a case. The occlusion at the first 
visit of the patient was entirely with the second molars, and the cut- 
ting edges of the upper and lower incisors were a quarter of an inch 
apart. As the patient had suffered during childhood from what she 
called " bone disease " she was afraid to submit to any treatment for 
bringing the anterior portion of the jaws nearer together. Gold crowns 
were placed over the lower first molars, to occlude with upper teeth, 
and increase the power of mastication. Within two or three years 
afterward the third molars erupted and opened the jaws to such an 
extent that the gold crowns lacked more than a sixteenth of an inch 
of touching the upper teeth. This case was undoubtedly due to the 
shortness of the ramus of the lower jaw. 

Treatment. — The simplest treatment of such cases is to grind down 
the cusps of the occluding teeth. In simple cases this can be done so as 
to enable the incisors to bite upon each other. (See Figs. 802 and 803.) 
The third molars may interfere so much that their extraction will be 
indicated. By the use of articulating paper the occluding points which 
need grinding may be easily located. 

In some cases there may be a malocclusion of the cusps only, so 
that grinding them away will be sufficient, while in other cases a con- 
siderable portion of the tooth must be ground away. Prof. Guilford 
suggests grinding as much as possible without causing too great pain, 
and then administering an anesthetic and continuing the grinding. 
" The sensitiveness of the exposed dentin may afterward be obtunded 
by repeated applications of either zinc chlorid, caustic potash [potas- 
sium hydroxid], or silver nitrate. Where neither of these will avail 
sufficiently, it may be advisable to devitalize the pulps of two or more 



LACK OF ANTERIOR OCCLUSION. 



789 



of the teeth most interfering with occlusion, and then continue grind- 
ing until the necessary change is effected." x 

The writer has lately applied cataphoresis successfully after having 



Fig. 805. 




Kingsley's appliance for forcing molars into their sockets. 

ground the teeth away till they were quite sensitive. The operation was 
thus continued two or three times in succession till the required reduction 

was effected. 

Fig. 806. 




Kingsley's appliance for forcing molars into their sockets. 

By the use of a chinpiece and cap on the head similar to that shown 
in Figs. 783 and 784 for reducing lower protrusion the anterior por- 
tion of the jaws may be closed. There are three possible solutions as 

1 Orthodontia, 2d ed., p. 195. 



790 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



Fig. 80/ 



to how the change is effected — (1) filling up of the glenoid cavity, (2) 
elongation of the condyle, or (3) the forcing of the molars into their 
sockets. The latter is the most plausible explanation, judging from 
experience in cases of Class 4. 

Fig. 805 shows an appliance devised by Dr. Kingsley for forcing 
the upper molars into their sockets, and described by him as follows : 
" A frame covered the bicuspids and molars of the upper jaw, with arms 
coming out of the corners of the mouth and extending along the cheeks 
to a point exactly opposite the centre of the pressure required within 
the mouth ; a small wire passed in front of the incisors to keep them 
from springing forward and two elastic straps connected this frame with 
the skull-cap exactly as seen in Fig. 806. Both these elastics were re- 
quired, partly to prevent any tendency of the recently moved incisors 
from carrying the whole apparatus forward, but particularly to keep the 
proper balance of the skull-cap, the strain of either elastic alone having 
a tendency to pull it out of place." 

Class 14. Excessive Overbite. — Etiology. — Overbite as illustrated 
in Fig. 807 is due (a) to lack of development of the posterior portions of 

the jaws and process, or (6) to excessive 
development of the anterior portions 
of the same so that the upper incisors 
and canines close entirely over the 
lower and hide them from view, while 
the cutting edges of the lower teeth 
impinge either upon the necks of the 
upper or upon the gums behind them, 
sometimes to such an extent as to 
penetrate the gum tissue. 

This condition is often associated 
with other irregularities ; particularly 
protrusion of the upper incisors, of 
which it may be the cause. 
While many cases may be improved by grinding the cutting edges 
of the lower incisors, it is not always sufficient, as the relative condi- 
tions remain the same. 

The treatment of such cases consists in (a) forcing the upper anterior 
teeth up into their sockets, (b) depressing the lower anterior teeth in 
their sockets, (c) causing the bicuspids and molars to erupt far enough 
to overcome the deformity, or (d) all three movements combined. 

If the whole fault lies with the upper incisors and canines from their 
having erupted too far, they may be forced up into their sockets by an 
appliance such as is illustrated in Fig. 808, reported by Dr. Kingsley in 
1866. It consisted of a gold frame over the cutting edges of the in- 




Overbite (Talbot). 



EXCESSIVE OVERBITE. 



"91 



cisors and canines. From this frame a post projected from each corner 
of the mouth, and from these posts strips of brass (detachable) extended 
upward and backward and were connected by elastic ligatures with a 




Kingsley's appliance. 

cap on the back of the head. It will be noticed that the attachment to 
the cap is above and forward of the ear. The cap should be so adjusted 
as to bring the pressure as much as possible in a line with the roots 
unless it be desirable to move the crowns backward at the same time, in 
which case attachment to the 
cap may be made below the 
ear as w T ell as above it, as 
shown in Fig. 766. 

Figs. 809 and 810 show a 




Case's appliance. 



case of overbite treated by Dr. C. S. Case, in which, he says, " the jaws 
were opened by permanently lengthening the posterior teeth." His 



792 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

method of treatment he describes as follows : " I inserted a simple black 
rubber plate that covered the roof of the mouth and possessed a thick- 
ened portion in front to receive the thrust of the six lower anterior 
teeth .... The posterior teeth were thus prevented from forcible 
occlusion until Nature had produced in them a sufficient growth and 
fixed them permanently in their extended positions." 

Unless such a plate rests on the inclined surfaces of the canines (and 
incisors also, in some instances) the force in biting will cause it to injure 
the soft parts on which it rests. To prevent it from moving the canines 
outward clasps should be extended around them, or the plate should be 
provided with a labial bow and clasps or extensions of the plate around 
the first or second molars, similar to the plate shown in Fig. 762, except 
that the plate should extend forward to the incisor teeth. The bow 
will prevent any forward movement of the upper incisors, and may 
even be used to reduce their prominence by pressure upon them. 

Dr. Cutter 1 of Cambridge, Mass., describes a case in which the 
posterior teeth were lengthened by a similar plate, and the lower jaw 
brought forward at the same time, by so shaping the plate that the 
lower incisors bit upon an inclined plane. (See Figs. 776 and 777.) 

Dr. Andrews 2 describes a similar case as follows : " I had a patient 
a little over twelve years of age, the cutting edge of whose lower 
incisors touched the upper gum so as to irritate it. A platform plate 
such as Dr. Cutter describes was worn for about two months. The 

Fig. 811. 




\ 
Writer's appliance for depressing lower incisors. 



lower centrals, laterals, and canines struck against the plate and allowed 
the bicuspids and molars to elongate. After a time I found there was 
one-eighth to a quarter of an inch space between the lower incisors and 
the upper gum in closing the mouth." 

Fig. 695 shows how the writer elongated upper and lower bicus- 
pids and molars so that they could occlude. The same plan might be 
followed with all of the bicuspids and molars at the same time, while 
the jaws are held open with such a plate as that shown in Fig. 810. 

1 International Dental Journal, vol. xv. pp. 353-355. 2 Ibid., pp. 382, 383. 



EXCESSIVE OVERBITE. 793 

Fig. 811 shows a plan for forcing lower incisors into their sockets. 
A metal cap is swaged to fit over the occlusal edges. To this is sol- 
dered a wire which extends out of the corners of the mouth and is bent 
into hooks at each end. From these hooks rubber bands extend to a 
chinpiece. To prevent this chinpiece from sliding forward it is neces- 

Fig. 812. 




Davenport's appliance for raising the bite. 

sary to extend a tape from it around the patient's neck. This appliance 
was suggested by the interdental splint. 

Fig. 812 shows an appliance for raising the bite, by Dr. W. S. 
Davenport, exhibited at a meeting of the American Dental Society of 
Europe, Aug. 5, 1895. " The means employed for correcting the irreg- 

Fig. 813. 




Case's appliance for raising the bite. 

ularity was to insert a bridge appliance, which was fastened by means 
of gold caps to the second molars, and brought forward a few lines 
above the molars and bicuspids, resting with a gold saddle on the six 
front teeth. In two weeks the arch was spread and the teeth were 



794 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

drawn up to a normal position by the use of ligatures which were 
looped around the bicuspids and molars, and fastened at the lingual 
surface, then tied to the masticating surface of the bridge above." 1 

Fig. 813 shows an appliance of similar character devised by Dr. 
C. S. Case. 2 The object of the appliance is to depress the lower incisors 
in their sockets, and raise the bicuspids, and first molar also, when 
possible, so as to change the whole line of occlusion and open the bite. 

On each molar — first or second according to the age of the patient 
— is placed a hollow crown, on the buccal surface of which is soldered 
an open tube or trough, opening upward. On each bicuspid is soldered 
a band with a buccal hook pointing downward, also on the first molar 
if the second has been used for supporting the hollow crown. On the 
incisors are cemented bands with hooks turned upward. A labial bow 
of elastic German silver or piano wire has its ends inserted in the 
troughs of the hollow crowns, its front resting above the hooks on the 
incisors and its sides pressed under the hooks on the bicuspids and 
first molar. The action is such as to depress the incisors and elevate 
the bicuspids and, if possible, the first molar also. The hollow crown 
should be high enough to open the bite the required distance. 

Class 15. Separation in the Median Line. — The simplest treatment 
of this irregularity is to draw the centrals together with a rubber band or 
with twisted silk or linen ligatures passed two or three times around the 
teeth. They can be retained by a wire band passing around both teeth. 

In some cases it is better to cement on the lateral incisors bands 
with tubes on the labial surfaces and draw them toward each other by 
means of a long drag-screw, as shown in Fig. 814. 

Fig. 814. 



Appliance for regulation and retention. 

The same appliance serves for retention by adding cement to the 
screw behind the nut to prevent its loosening. The advantage of this 
plan is that the space is left next to the canines instead of between 
the centrals and laterals, and also that the centrals will be more easily 
retained in their new position if they are supported by the laterals. If 
the central incisors are far apart and the roots are parallel, they will 
slant too much when moved together as described. It is necessary 
1 Dental Review, Feb. 15, 1896, p. 126. 2 Ibid., Dec. 1895, p. 867. 



MOVING THE ROOTS OF TEETH. 



795 



to also move the roots of these teeth ; the method of performing that 
operation is described in the following section. 

Moving the Roots of Teeth. 

In the foregoing methods of moving the teeth the apex of the root 
remains stationary and the crown swings from that point like a pen- 
dulum. In most cases that is the only movement necessary, in 
others it is the only movement possible, yet in many cases it is very 
undesirable. 

The first published appliance for moving the apices of the roots of 
teeth was that described by Dr. J. N. Farrar. 1 (See Figs. 815 to 818.) 



Fig. 815. 



Fig. 816. 





Fig. 817. 





Fig. 819. 



The central incisors were separated as shown in Fig. 815, the roots 
being parallel. In drawing them together by a clamp band (p) the 
teeth tilted toward each other until they touched at 
the mesio-incisal angles (/, Fig. 816). Up to this time 
the apices of the roots were practically the fixed points, 
and the alveolar process between the roots was con- 
densed and absorbed as the teeth moved. As soon 
as the crowns touched each other at the mesio-incisal 
angles these became the fixed points, and, as the power 
was still continued at the necks of the teeth, the roots began to move 

1 Dental Cosmos, vol. xxiv. p. 190. 




Incisor guide. 



796 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



till they were practically parallel (Fig. 818). To prevent the crowns 
sliding past each other and overlapping, a guide was constructed as 
shown in Fig. 819. The same appliance will serve for retention. 

If after extracting a crowded lower incisor the teeth on each side 
of the space are found to lean toward each other, as in Fig. 820, 

Fig. 820. 




Appliance for moving roots of lower incisor and cuspid. 

the roots may be moved toward each other so that the crowns will 
be parallel to each other. Dr. C. S. Case has devised an appliance 
for this purpose, shown in Figs. 821 and 822. Bands are fitted 
to the teeth on each side of the space, and sometimes to the second 
tooth also. From these bands stiff bars extend downward parallel 
with the surface of the gum from an eighth to a third of an inch below 



Fig. 821. 



Fig. 822. 




Appliance for moving roots. 

the margin. On the lingual surface similar bars extend about the 
same distance. On the free ends of the bars are soldered hooks or 
headed pins, so that a rubber band or a ligature can be extended 
from one labial bar to the other, and from one lingual bar to the 
other. The direction of force is thus brought low enough to move 
the roots as well as the crown of the teeth. Suture wire may be 
substituted for the rubber band or ligature for retention. 

In some cases of upper protrusion the alveolar process is so promi- 
nent that when the crowns of the teeth are moved back to the desired 



MOVING THE ROOTS OF TEETH. 



797 



position the roots have not moved with them, and the upper lip is 
still too prominent. So also in some cases the palatal portion of the al- 
veolar ridge is so dense that it does not yield readily, and as the crowns 
move backward the edge of the process acts as a fulcrum and the ends 
of the roots move forward. The prominence of the lip is thus increased. 

In the World's Columbian Congress, 1893, Dr. C. S. Case showed 
casts and models of such cases and appliances by which the roots and 
the whole anterior alveolar process can be moved back and the promi- 
nence of the upper lip reduced to a normal contour. For illustrations 
and descriptions of this operation the reader is referred to Chapter 
XXV., and especially to Figs. 847, 853, 854, 855, 896, and 897. 

Fig. 823 shows Dr. Farrar's appliance for moving forward the 
roots of incisors by working on the lingual side of the arch. " The 

Fig. 823. 




Farrar's appliance for moving incisor roots forward. 



Fig. 824. 



base of support is a transpalatal screw-jack, anchored by two clamp 
bands that embrace the side teeth ; from this jack to the posterior sides 
of the necks of the incisors and lying close to the sides of the arch are 
two other screw-jacks to press against these front teeth. To hold these 
jacks upon them, each incisor has upon it a 
broad ferrule (cemented) with a U-shaped lug 
on the lingual side, near the gum (see F, in 
the lower part of Fig. 823), in which a bar 
connecting the anterior ends of the jacks rests. 
To hold firmly the end of the crown of each 
incisor, and prevent them from moving for- 
ward when these jacks are set at work against 
the necks of the teeth, the ends are tied to the 
transpalatal jack by two wire cords connecting 
with a crossbar lodged in other U-shaped lugs soldered to the labial side 




Showing attachment of cross- 
bar. 



798 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



of the ferrules near the ends of the teeth, as represented by Fig. 
824." 

Fig. 825 shows another of Dr. Farrar's appliances for the same 
purpose, which makes use of a labial bow for retaining the ends of 



Fig. 825. 




Farrar's appliance for moving roots forward. 



the incisors, and omits the transpalatal jack, thus simplifying the 
apparatus. 

Fig. 826 shows Dr. Farrar's appliance for drawing back the roots 

of upper incisors. " The crowns 
Fig. 826. are gtayed by an inside rectan- 

I / / gular frame resting in U-shaped 

lugs at the ends of the crowns 
and braced against nuts soldered 
to two anchor clamp bands on 
the side teeth. The roots are 
drawn back by a labial bow, at- 

Fig. 827. 





Cross section. 



Farrar's appliance for moving roots back. 

tached to the clamp bands by screws. Fig. 827 shows a cross section 
of such an appliance. 



IMMEDIATE MOVEMENT OF TEETH. 



799 



Immediate Movement op Teeth. 

The forcible rotation of a tooth by the forceps was recommended by 
Mr. John Tomes. 1 He said the operation had been frequently performed 
by himself and others, without devitalizing the pulp except in one hos- 
pital case ; that the best age for the operation was eight or nine years ; 
that he had performed it for patients thirteen years of age and for one 
patient of fifteen. The operation has been performed by many since 
then, and for older patients also, being preferred by some to the longer 
but less painful plan usually followed. 

The beaks of the forceps should be carefully fitted to the neck of 
the tooth, which should be protected by sandpaper, emery cloth or lead 
foil. Tomes recommends that in some cases the tooth be rotated half 
way at first, then allowed to rest for a couple of weeks before being ro- 
tated to place. The operation is confined, of course, to teeth with straight 
conical roots. Even a slight curve in the root such as is frequently 
found with the lateral incisor would render the operation impossible. 

Immediate Regulating of Inlocked Teeth. — Dr. L. C. Bryan 2 has 
advocated the immediate movement of single teeth, situated inside the 



Fig. 828. 




arch, especially canines and laterals. The following is his description 
of the operation : " The treatment which I have finally adopted is to 
inject cocain and either partially cut away the thick intervening alveolar 
process with drills and fissure burs, or, when the process is thin, bodily 
wedge the outer alveolar wall away with a half-round wedge-shaped 
chisel, by inserting the point of the instrument between the crown and 
the bone and forcing it up along the root until enough space is secured 
for the tooth to be brought out into place outside the lower tooth. This 

1 Tomes, Dental Surgery, 2d ed., p. 162. 2 Dental Review, 1892, vol. vi. p. 859. 



800 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

latter I formerly accomplished by pressing the wedge-shaped instrument 
or the inner beak of a suitably formed forceps up along the lingual sur- 
face of the tooth until the crown was forced outward sufficiently to be 
firmly grasped. It was then brought gradually out into place." 

Another and better plan was by the use of forceps specially made 
for the purpose, shown in Fig. 828. 

Following is a description of an operation by Dr. Bryan, at the 
World's Columbian Dental Congress in Chicago, August, 1893, from 
the report of the Committee on Clinics : l " The patient, a fifteen-year- 
old girl, had a right upper lateral incisor locked behind the lower 
incisors with sufficient space between the upper central and canine for 
immediate regulation. Cocain was injected and a perpendicular incision 
was made with a small circular saw through the gum and half through 
the alveolar septum on both sides of the root of the lateral from the 
apex of the root to the crown of the tooth. A three-inch flat steel 
guard, lined on the gum side with rubber ■£§ of an inch thick, was 
fitted to the curve of the gum and formed a rest for the long, round 
front beak of the forceps ; the other beak rested against the distal wall 
of the lateral up to the gum. "With slight pressure the connection of 
the tooth with the distal alveolar wall was severed, and the tooth came 

Fig. 829. 




Immediate movement of bicuspid (Cunningham 



easily forward to its place in the arch in front of the lower teeth, bring- 
ing with it the front wall of the alveolus, firmly attached to the root 
and ready to heal quickly and reunite with the neighboring borders of 
alveolus. The apex of the root was not disturbed in its position, so that 
the nerve and vessels would remain intact, as will always be the case 
if the operation is correctly and carefully performed." 

Moving- Several Teeth by the Immediate Method. — Dr. Geo. 
Cunningham of Cambridge, England, began the use of this method in 

1 Transactions, vol. ii. p. 997. 



IMMEDIATE MOVEMENT OF TEETH. 



801 



1886 by forcing with the forceps an inlocked bicuspid into the position 
of a molar which he had just extracted. The tooth became firm in its 
new position, but the pulp did not survive the operation. Figs. 829 and 
830 were made from photographs of casts of the case, before and after 
treatment. 

Fig. 830. 




Immediate movement of bicuspid (Cunningham). After treatment. 

Figs. 831 and 832 show casts of a case in which he forced five teeth 
into new positions. The following is his description : u The patient hav- 
ing been anesthetized (nitrous oxid and ether), the molar was extracted, 
and after fracture of the alveolar process between the teeth both bicuspids 



Fig. 831. 



Fig. 832. 




Immediate movement of five teeth (Cunningham 



were luxated backward by means of Physick's forceps. The canine and 
lateral incisor were similarly treated with the additional help of guarded 
ordinary forceps. On endeavoring to luxate the central incisor, owing 
to a curved and distorted root, it slipped down between the beaks of the 
forceps, and thus became completely dislocated from its socket and all 

51 



802 ORTHODONTIA AS AN OPERATIVE PROCEDURE. 

its normal attachments .... Considerable force had to be exerted to 
thrust it into its new position." The teeth were ligated, etc. 

Among other directions he gives the following : " All being ready, cut 
the alveolar process with a thin saw -J of an inch to 1 J inches in diameter, 
not thicker than note-paper, into such sections as are necessary .... 
Forceps, elevator, or other instrument is used for pushing, pulling, or 
rotating the tooth sections into place." 

He advises that the teeth should be retained by ligatures of silk or 
wire or a splint of German silver or platinum bands soldered together, 
and that the articulation of the teeth be adjusted by grinding, etc. 

Immediate or surgical regulating is not recommended by these advo- 
cates for all cases, but only for those in which all circumstances favor 
it, such as lack of time for other treatment, desire of patient, yielding 
alveolar process, abundance of room, etc. While it is a possible opera- 
tion, it will never become a frequent one. 

Combined Method, Surgical and Mechanical. — Dr. Talbot advo- 
cates the surgical removal of a portion of the alveolar process in 

Fig. 833. 




Surgical retraction of lower cuspids (Talbot). 

the path of the advancing tooth while a tooth is moved by usual 
means, thus avoiding the delay caused by the slow process of 
absorption. This is especially advantageous in case of very dense 
tissue and in cases in Avhich it is difficult to secure sufficient 
anchorage. By thus removing the chief obstruction, teeth may be 
moved by depending on an anchorage that in ordinary cases would be 
entirely inadequate. He says : x 

" For seventeen years I have adopted surgical treatment, but have 
not made public my methods, since incidental conversation with some 
1 Dental Cosmos, 1896, vol. xxxviii. p. 909. 



IMMEDIATE MOVEMENT OF TEETH. 



803 



of the best men from time to time revealed that they had not taken 
kindly to it. I therefore wished to give it sufficient trial before 
recommending it to the profession. I have met with such markedly 
uniform success that I do not hesitate to recommend it to all practi- 



Fig. 834. 




Surgical retraction of incisors and cuspids (Talbot). 

tioners as perfectly safe and reliable with the antiseptic care required 
in surgical operations. This method consists in removing entirely the 
alveolar process in the line of travel of the tooth to be moved, leaving 
a small amount of process about the root of the tooth, holding intact 

Fig. 835. 




Surgical correction of malposed cuspid (Talbot). 

the peridental membrane. This is accomplished with coarse-cut Reve- 
lation burs, or those that will cut in all directions. They can thus be 
used as drills in certain conditions to be mentioned later on. 

" If the canines require to be carried backward, make an appliance 
with bands about the first and second molars, with cap upon the canines 
and a bar with screw and nut upon the end, as recommended by Dr. 



804 



ORTHODONTIA AS AN OPERATIVE PROCEDURE. 



Farrar. Extract the first bicuspid and adjust the appliance ; use a sharp 
new bur dipped in five per cent, carbolic acid or one per cent, corrosive 
sublimate or listerine. Then, resting the hand against the canine, cut 
out the palatal and buccal V-shaped plate, making a concave surface 
of the alveolar process, as illustrated in Fig. 833. 

"If the upper incisors are to be carried back, cut semicircular 
spaces just posterior to the teeth to be moved (Fig. 834). To carry a 
canine into place which is erupting into the vault of the mouth, remove 
the alveolar process in the direction of the line of travel (Fig. 835). 

" In moving teeth laterally by a jack-screw, it will be found that not 
infrequently one tooth moves faster than the other. To bring both to 
their proper position cut out the alveolar process on the side of the 
slowest-moving tooth, and both will come into proper position (Fig. 836). 
To rotate a tooth, cut a circular groove as deep as possible around the 
tooth, leaving enough process to hold the peridental membrane intact 
(Fig. 837). In this manner teeth may be moved very rapidly and with- 



Fig. 837. 



Fig. 836 




Spreading cuspids (Talbot). 



Rotation (Talbot). 



out much pain. This should always be done by means of screws. By 
this method we have the tooth or teeth to be moved completely under 
control. Any of the teeth in the mouth may be used for the fixed 
point of resistance, thus doing away with all unsightly appliances out- 
side the mouth. When in place, they should be anchored in the usual 
manner. Antiseptic washes should be used from time to time, such as 
one per cent, corrosive sublimate, listerine, or five per cent, carbolic acid. 
" In operations of this nature the peridental membrane and also the 
periosteum are apt to be injured. This was the particular question in 
recommending it to the profession. Although I have had a few cases 
of infection, I am quite certain now that such injuries are not of any 
serious consequence, since with proper precaution no bad results will 
follow." 



CHAPTER XXV. 

THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

By Calvin S. Case, D. D. S., M. D. 



I. Influence op the Teeth on the Physiognomy. 

In the developmental processes of animal life the teeth have proba- 
bly been more influential than any of the other organs in shaping the 
bones of the head — especially in determining the physical characteristics 
of the physiognomy. The physical shape and structure of the jaws 
conclusively show the influence that the teeth have exerted in different 
species in response to Nature's law to propagate that which would best 
subserve them in the performance of their functions. The importance 
of the teeth, therefore, and their inherent demand upon surrounding 
anatomical structures for proper means of development, sustenance, and 
use, is evidence that they exert, during development, a more or less im- 
mediate influence in determining the size and shape . of the maxillary 
bones, and thus indirectly are extensively influential in characterizing 
the individual shape of the human face. 

Often the position of the anterior teeth and alveolar process is such 
as to impress upon the contiguous features, even in repose, certain con- 
ditions which vary from a slight imperfection in esthetic contour to a 
most distressing facial deformity. Nor are these dento-facial imperfec- 
tions always wholly due to a malposition of the teeth, so much as to a 
lack of normal symmetry in the size or shape of the maxillary bones 
upon which so large an area of the face is dependent for its contour. 
These conditions may have arisen from the direct inheritance of a 
parental deformity, or from the inharmonious union of unaltered types, 
as the teeth of one parent and the jaws of another. It is equally true 
that the union of harmonious types often results in symmetrical condi- 
tions which neither parent possesses. 

Among local causes, or those which operate after birth in the pro- 
duction of facial imperfections, may be mentioned habits, impaired 
dentition, delayed and injudicious extraction of the deciduous teeth or 
first permanent molars, and mal-occlusion. 

The influence of the teeth during the time of their eruption (produ- 

805 



806 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

cing on the one hand the excessive pressure of large teeth and concomi- 
tant alveolar development, and on the other a lack of pressure from an 
irregularity or injudicious extraction) in effecting a change in the in- 
herent shape or size of the maxillary bones beyond that which the 
alveolar process is forced to assume to accommodate them, has been a 
question of considerable controversy. It is reasonable to assume, how- 
ever, that natural influences exerting a slight force upon the immature 
maxillary or other bones, during early stages of their growth, would 



Fig. 838. 



Fig. 839. 





Fig. 840. 



have somewhat the same effect that is known to be possible later by 
artificial force. 

The following case will serve to illustrate this principle : 
Patient aged thirteen years. When presented the upper incisors 

were fully the width of a tooth posterior 
to a normal position, and so badly in- 
locked, in occlusion, that the crowns were 
nearly hidden behind the lower. (See 
Fig. 838.) With the exception of the 
upper canines, which were forced slightly 
out of alignment, all the other teeth in 
both jaws were in proper position and 
occlusion. (See Fig. 839.) The posterior 
position of the inlocked incisors was not 
due, in the slightest degree, to a lingual 
inclination of their crowns, but the re- 
trusion extended to the roots as well 
and seemed to involve the intermaxil- 
lary process, producing a decided depression of the overlying featureSc 
(See Fig. 840.) 

The probable history of the cause of this condition is as follows : 
The lower incisors erupted much earlier than the upper, and there being 




INFLUENCE OF THE TEETH ON THE PHYSIOGNOMY. 807 

a short-bite occlusion, as soon as the upper incisors began to erupt they 
became inlocked with the lower incisors. At this time the roots and 
surrounding processes were in an immature condition. As the crowns 
continued to erupt they slid down the posterior faces of the lower in- 
cisors, where they were retained during the continued development of 
the roots in the opposite direction, the force being sufficient to prevent 
the natural growth and development of the entire intermaxillary process, 
which normally would have carried them bodily forward to an harmo- 




(Before.) (After.) 



nious position. As the oilier teeth came into place the lateral portions 
of the jaw were allowed to normally develop in harmony with the natural 
growth of the other parts. Thus the canines and bicuspids were found 
in their proper relative positions as regards the lower. 

Fig. 842. Fig. 843. 





Force was applied with the contouring apparatus described in section 
VI. of this chapter. In less than six months the incisors were carried 
bodily forward in an upright position, together with the entire surround- 
ing alveolar ridge and intermaxillary process (see Figs. 841 and 842), 



808 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



Fig. 844. 




with a perfect correction of a very unhappy facial deformity. (See 
Fig. 843.) Fig. 844 is from a photograph taken three years after the 
completion of the operation. 

In dental orthopedia we possess the great advantage over general 

orthopedia of applying force directly 
to the bone itself, through the medium 
of the teeth, without the intervention 
of the soft and sensitive tissues. 

The teeth imbedded in the alveolar 
process, that in turn is firmly united to 
the true bone, may be considered, when 
in the grasp of a regulating machine, 
as an integral part of it, firmly and di- 
rectly attached to that part of the bone 
we desire to move, and capable of 
exerting the quality and direction of 
force the machine gives to them. 
This force being applied unitedly to a number of teeth standing side 
by side, the surrounding and contiguous bone — which is largely a can- 
cellated structure — is carried bodily in the direction of the force ; not 
by the fracture of its substance or to any great extent by a metamor- 
phosis of tissue, but by the bending, condensation and elongation of its 
cellular structure ; the whole adapting itself to a new form, in which 
position the immediate interstitial tension of its particles is soon relieved 
and brought to equilibrium by Nature — though it may require to be 
held in that position for many months before there is an entire relief 
from the inherent tendency to return to the primary position. 

In contemplating the treatment of a dental irregularity a careful 
study of the physiognomy in different attitudes of expression should be 
made, with the view of determining the relative position of teeth and 
facial contours. The value of a careful preliminary facial examination 
and comparison cannot be overestimated, for it is often the only guide 
to correct treatment. 

For instance, since it has become possible to expand or retract the 
anterior portion of the upper apical arch with the surrounding bone in 
which the moving roots are imbedded, we are no longer confined to the 
possibility, and frequent questionable propriety, of permanently moving 
the lower jaw forward or backward to correct a facial deformity which 
pertains exclusively to the upper maxillae and middle features of the 



face. 



H. Principles of Facial Orthopedia. 



The portion of the human face that it is possible to change with a 
dental regulating apparatus may be said to lie between two diverging 



PRINCIPLES OF FACIAL 0RTH0PED1A. 



809 



Fig. 845. 



lines which arise at a point below the ridge of the nose and curve down- 
ward to inclose the alee and depressions on either side ; thence laterally 
to encircle a portion of the cheek, and downward to inclose the entire 
chin. (See Fig. 845.) 

Within this ovoidal area are the main features of expression. 
Within this space the slightest change of 
contour will often produce a marked effect 
upon the entire physiognomy and give a 
different expression to the countenance. 
It is here that an inherited or an acquired 
lack of symmetry in the size, shape, or 
position of the teeth and jaws produces 
those marked changes of facial contour 
which characterize different physiogno- 
mies. This area may be termed the 
" changeable area " in contradistinction to 
the more stable features, or "unchangeable 
area." 

For convenience of ready reference, 
the features in that portion of the change- 
able area which are bounded laterally by 
the naso-labial lines may be divided into four segments as follows : 

Segment 1. — The end of the nose and the upper portion of the upper 
lip, including the naso-labial depressions. 




Fig. 846. 



Unchangeable area . 



Changeable area ■ 




Segment 2. — The lower portion of the upper lip. 
Segment 3. — The lower lip. 
Segment 4- — The chin. 



810 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

In the preliminary examination of the physiognomy from a purely 
esthetic standpoint with a view of correcting a dento-facial deformity 
or imperfection by applying force to the teeth, there are certain promi- 
nent features to be especially observed and their relative position care- 
fully noted. These may be divided into two classes : first, those which 
lie in the unchangeable area, as the forehead, bridge of the nose, and 
malar prominences; second, those in the changeable area. 

The four segments in the latter class shown in Fig. 846 are change- 
able in their relations to each other, and also in their individual relation 
to features in the unchangeable area. For instance, it is possible to pro- 
trude or retrude the upper portion of the upper lip with the depressions 
on each side of the nose, the nasal septum, and the end of the nose, 
without changing the lower portion of the upper lip in its relation to 
other parts. (See Fig. 855.) The same is true of the other segments 
— in fact, a retrusion of the second segment and a protrusion of 
the first may be accomplished at the same time. (See Figs. 853 
and 854.) 

If the lower jaw be mechanically protruded or retruded bodily, the 
lower lip will of necessity be carried forward or backward with the 
chin, unless a special operation is performed on the lower teeth to pre- 
vent it from changing its relations to the upper lip. 

Those portions of the changeable area which lie over the bicuspids 
and first molars — shown in Figs. 845 and 846 — and separated from the 
lips by the naso-labial lines, may be considered as separate segments, as 
the causes which influence a change in the contour of the cheeks differ so 
decidedly from those which change the more anterior areas. The lateral 
expansion or contraction of the dental arches will often change the con- 
tour of the cheeks with no effect upon the labial area, if the anterior 
teeth remain unchanged in position. Again, a decided retrusion of the 
anterior teeth and process with no lateral expansion of the arch will 
invariably result in giving to the cheeks a fuller contour, by relieving 
the tension of muscular tissues. The same result will often be obtained 
in closing the characteristic open bite of a mouth-breather by grinding 
the posterior teeth, and also by retracting a prognathous lower jaw. 

In a study of profiles we frequently observe a lack of perfect har- 
mony in the position of the chin. The lower jaw is apparently 
protruded, or retruded, so as to mar the esthetic perfection of the 
physiognomy, and yet were these same faces examined by a trained 
observer he would find in a large proportion the lower jaw in perfect 
harmony with the unchangeable area, and that the appearance of its 
malposition was an effect due wholly to a protrusion or retrusion of the 
upper jaw and teeth. In other words, it is a common error to imagine 
the chin imperfectly posed because it is not in harmonious relations to 



UPPER DENTAL AND MAXILLARY PROTRUSIONS. 811 

the other features of the changeable area, instead of comparing it, 
as we should do, to the more stable or unchangeable features of the 
physiognomy. 

In examining the physiognomy of a patient, the head should be in 
an upright position, on a line with that of the observer, and the face 
studied from different angles while in repose and in action. 

AVhile looking at the profile in repose the most important thing to 
determine is the relative position of the chin with the forehead, malar 
prominences, and bridge of the nose. If its position is harmonious 
with the unchangeable area and the lower lip is well posed, it indicates 
that the operation of facial contouring should be performed — if any- 
where — upon the upper jaw and teeth. For if the first and second seg- 
ments are abnormally protruded it will cause a chin to appear retruded 
that is perfectly harmonious in its relations to the principal features of the 
face. (See Fig. 847.) Again, a retruded or contruded upper arch with 
a depression of those features which are supported by the upper maxilla? 
will cause a perfectly posed lower jaw and chin to appear protruded or 
prognathous ; as instanced by the cases illustrated in sections I. and IV. 
in which the facial effect, before treatment, was that of protruded lower 
jaw, but which were perfectly corrected by an anterior movement of 
the upper incisors and intermaxillary processes. 

HI. Upper Dental and Maxillary Protrusions. 

Figs. 847 and 848 will serve to illustrate the class of facial de- 
formities known as abnormal upper protrusions, and the advantage of 
retruding the upper anterior teeth and surrounding process. 

Fig. 847. 




In Fig. 847 wide interdental spaces between the upper teeth per- 
mitted the reduction without extracting. In Fig. 848 the upper first 
bicuspids were extracted. 



812 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

If the operation of "jumping the bite" were performed in these 
cases, there would no doubt be an improvement of the original appear- 
ance of the physiognomy, by the bringing of the chin and lower lip 
into more perfect harmony with the upper ; but this would not be cor- 
rect treatment, because, as will be observed, the chin is in not far 

Fig. 848. 




from perfect position when compared with other features of the un- 
changeable area. 

The principles involved in the correction of this class of facial 
deformities may be diagram matically illustrated as follows : 



Fig. 849. 



Fig. 850. 




Fig. 849 is a profile view of a typical case of abnormally protruded 
upper jaw. It will be observed that the chin appears retracted. 

Fig. 850 shows the improved effect that would be produced by 



UPPER DENTAL AND MAXILLARY PROTRUSIONS. 



813 



"jumping the bite " in bringing segments 3 and 4 into more perfect 
harmony with segments 1 and 2 ; yet not to be compared with that per- 
fection of symmetrical contour shown by Fig. 851, where the chin and 
lower lip are permitted to remain in their original harmonious position 
while the end of the nose and upper lip are retruded into harmony with 
the whole. 

The three faces have been made exactly alike with the exception — 
as shown by the cross lines — of certain mechanical movements of the 
profile outlines in the changeable area. In Fig. 850 the outlines of 
segments 3 and 4 are forced farther forward, and in Fig. 851 segments 



Fig. 851. 



Fig. 852. 




1 and 2 are carried back as they would be by a retruding apparatus 
attached to the teeth. 

In comparing Figs. 849 and 851 the difference in esthetic effect is 
quite striking, and it is one also which would seem to be hardly possible 
with so little change in the outlines of a comparatively small area. By 
cutting a piece of black paper to the exact outlines of Fig. 851 and 
placing it upon Fig. 849 the real and only difference in the two figures 
can be plainly seen — as in Fig. 852. 

When such a change is produced in the features of a human face the 
difference is greatly enhanced because of the harmonious perfection of 
other contours not shown by the figures. 

It is a noteworthy fact that a very little change in the peripheral 
shape or position of certain bones of the face on which the features are 
dependent for their character and form — a change so trifling that it could 



814 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

hardly be measured — resulting in a slight filling out or depression of 
certain contours, will often beautify to a remarkable degree the ap- 
pearance of a face that would otherwise be quite plain and unattractive. 

This is true of all the more common cases of upper protrusion and 
retrusion which show an abnormal prominence or depression along the 
upper as well as the lower portion of the upper lip, and especially of 
those which seem to involve the entire intermaxillary process, influ- 
encing the antero-posterior position of the wings and end of the nose. 

In cases of protrusion, by applying a retracting force especially 
directed to the roots and crowns of the anterior teeth, the surrounding 
alveolar process and anterior portion of the maxillae will be forced 
back, allowing the upper lip to fall into a more graceful and easy pose, 
leaving the nostrils less broad and open, the upward curve of the nose 
straightened, and its pug-like appearance removed. 

When an upper protrusion is due alone to a labial inclination of 
large crowded teeth, with no marked protrusion over the apical zone, or 
in segment 1, the extraction of the first or second bicuspids is indicated, 
and the application of force to the crowns at such points and in such 
direction as will best overcome the malposition. 

Many instances have arisen, in the practice of dentists who were 
opposed to the extraction of teeth, where the above condition has 
actually been produced in the operation of crowding irregular teeth into 
alignment that were too large for an already perfectly harmonious 
maxillary arch. (See Figs. 875 to 878 inclusive, in section V.) 

There are innumerable instances where a labial inclination of both 
the upper and lower anterior teeth produces a pronounced protrusion of 
the lips with a very unpleasant expression in their management, espe- 
cially if in occlusion the lower anterior teeth are even with, or in front 
of, the uppers. The fact that the most natural occluding position of 
the lower front teeth is somewhat posterior to the upper teeth permits 
the graceful curve of the lower lip which is so necessary to the esthetic 
perfection of the chin. 

In order to correct a pronounced facial deformity of this character 
produced by large teeth crowded into arches that are too small for them, 
but otherwise harmonious in size, it will often be necessary to extract a 
bicuspid from each side from both the upper and lower jaws. Some- 
times the extraction from the lower of a central incisor will be suf- 
ficient. 

Instances frequently arise where the position and labial inclination 
of the upper anterior teeth produce a relative protrusion of the incisal 
zone and a contrusion of the apical, with a protrusion of the lower 
portion of the upper lip and a slight depression of the upper portion, 
deepening the naso-labial depressions. If the depression of segment 1 



UPPER DENTAL AND MAXILLARY PROTRUSIONS. 



815 



be not too pronounced, it may be restored by a slight forward movement 
of the anterior apical zone, accomplished in the retrusion of the incisal 
zone — by force applied at the incisal ends of the teeth alone, with the 
view of producing, as far as possible, a fulcrum force at the lingual 
margins of the alveoli. 

If the malformation is produced by an inharmonious union of 

Fig. 853. 




maxillae and teeth, as in the former case, the extraction of an upper 
bicuspid from each side will be indicated. Figs. 853 and 854 were made 
from the models of a case of this character, before and after treatment. 
The upper first bicuspids had been extracted some time before the 
patient presented for treatment. 

In contradistinction to this class of deformities, there is another 

Fig. 854. 




quite as common — though not so frequently recognized as an abnor- 
mality — in which all the conditions are reversed, in that the teeth have 
a lingual inclination with protrusion of the apical zone and maxillae. 

The teeth of these cases are commonly regular in alignment, and 
owing to their lingual inclination the occlusal zone may be in proper 
relative position. (See Fig. 855.) 



816 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

The facial imperfection which consists principally in a prominence 
or bulging along the higher portions of the upper lip and in the region 
of the nasal alee is often quite pronounced. When this is caused partly 
by the canine roots the difficulties are much increased in the case of 
patients older than thirteen. The fact that the roots of the canines are 
surrounded by the most dense portion of the alveolar process, and their 
movement bodily in a posterior direction requiring the resorption of a 
large portion of bone, makes this operation one of the most difficult in 
dental orthopedia. 

Fig. 855 is from the models of a patient over twenty years of age, 

Fig. 855. 




and will serve to illustrate a case before and after treatment of abnormal 
protrusion of the roots of the upper anterior teeth, alveolar process and 
maxillae — the axis of the incisors being inclined lingually. 

It will be observed that the canines have been moved bodily in a 
posterior direction notwithstanding the advanced age of the patient. 

If regulating appliances are properly constructed that will permit 
the production of an independent static fulcrum at the occlusal ends of 
the teeth, so that the entire power of the machine may be directed and 
maintained upon the roots (see Figs. 896 and 897, in section VI.) per- 
fect contrusion of the prominence will slowly but surely result. 



UPPER DENTAL AND MAXILLARY RETRUSIONS. 817 

If the teeth are crowded, overlapping, or turned on their axes, a 
correction of alignment may require the extraction of a bicuspid on 
each side in order to regulate them without an abnormal protrusion of 
their crowns. This is especially indicated when much retrusion of the 
canine roots is desired. 

IV. Upper Dental and Maxillary Retrusions. 

Facial imperfections which are due to insufficient fulness of contour 
in the central features of the physiognomy are quite common, and vary 
in degree from conditions that are hardly noticeable to those which may 
well be classed among the most unhappy of facial deformities. 

There are two distinct classes of this type of facial irregularity — 
one being due to a lack of development of the intermaxillary portion 
of an otherwise harmonious upper jaw ; the other to the fact that the 
entire upper jaw itself is too small and too posteriorly placed, in its 
relations to other parts. 

The teeth and alveolar process of the retracted parts are prevented 
from assuming harmonious relations, and consequently the overlying 
features are more or less depressed in proportion to the contruded or 
retruded frame upon which they depend for their contour. 

The primary cause of these conditions may be often very obscure 
and admit of nothing more tangible than conjecture, and, not unlike 
many of the causes of irregular teeth, be really immaterial to the work 
of correction. 

It may have been caused by the exertion of local physical forces 
during the early years of immaturity (as, for instance, the mal-eruption 
and occlusion of the teeth) ; or a local disturbance and interruption of 
nutrition from prenatal or postnatal causes ; and lastly, but by no means 
rarely, by inherent physical tendency. 

Class 1 : Retruded Upper Incisors and Intermaxillary Process. — 
In the more pronounced deformities of this class the physiognomy 
will often appear flattened, with prominent cheek bones and protruding 
chin and lower lip ; the upper incisors occlude evenly with or posterior 
to the lower incisors, and at times are extensively inlocked in this posi- 
tion, as instanced by the case fully described and illustrated in section I. 

The upper incisors, Avhich alone have their origin in the intermax- 
illary process, are in their entirety posterior to a normal relative posi- 
tion. The labial inclination of the crowns, together with the deepened 
incisive fossse, will show at once the contruded position of the roots and 
their maxillary surroundings. 

The upper lip resting upon the retruded teeth and the overlying 
process is proportionately depressed. Nor does the facial defect end 
here. The entire lower portion of the nose, supported as it is by the 

52 



818 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



Fig. 856. 



nasal cartilages which spring from the anterior nasal spine and lateral 
borders of the nasal orifice, is often decidedly affected in shape by the 
retracting influence of its supports. 

When there is a decided retrusion of the entire upper lip and lower 
portion of the nose, with alse resting in deep depressions caused by the 

unusual prominence of the naso-labial 
folds, the effect is that of an abnormal 
protrusion of surrounding parts, pro- 
ducing at times a startling expression 
of maturity that is only common to 
persons of advanced age. This expres- 
sion can be seen in Fig. 856, which is 
that of a girl only twelve years of age, 
and will serve as a type of cases com- 
monly met with in practice. 

Class 2 : Retruded and Contracted 
Dental and Maxillary Arch. — In this 
class of deformities the physiognomy, 
in the more pronounced cases, has much the same characteristics as 
those described above, but presenting a more general retraction of 
the central features, with less pronounced naso-labial folds. The nose 
is often thin and the nostrils pinched ; and though the end of the nose 
may be depressed, the distance from the tip to the more depressed lip 
is often lengthened. If the patient is a " mouth-breather " with the 




Fig. 857. 



Ftg. 858. 




typical " open bite," the deformity and the difficulties attending its 
reduction will be greatly increased. 

Fig. 857 is from a profile model of a face of this class. Fig. 858 
is from the same model photographed at a slightly different angle to 
show the angularity of the features. 

Fig. 859 is a view of the teeth in natural occlusion. The first lower 



UPPER DENTAL AND MAXILLARY RETRUSIONS. 819 

bicuspids have been removed preliminary to retruding the anterior teeth 
to reduce the abnormal protrusion of the 
lower lip and esthetically deepen the 
curve between the border of the lip 
and the chin. The figure has the ap- 
pearance of a perfect occlusion of all 
the molars, whereas, on account of the 
very great narrowness of the upper jaw, 
the buccal cusps of the second molars 
only, occluded with the lingual cusps 
of the lowers. 

Fig. 860 shows palatal views of the 
upper arch before and after treatment. 

Fig. 861 is a view of teeth in natural 
occlusion after treatment. The entire upper dental arch, especially at 
the apical zone, was considerably enlarged. The " open bite " was par- 
tially closed by grinding the molars and partly by extruding the teeth 
anterior to the molars with small rubber bands extending from the 
upper to the lower teeth. Fig. 862 is from a model of the face after 
treatment. 

As mentioned in section II., a depression of the central features 
such as described is often mistaken for a prognathous jaw, and treated 

accordinglv. 

Fig. 860. 





A slight retraction of the lower jaw will in nearly every case of this 
character produce an improvement in the facial aspect, because the chin 
and lower lip are brought into more perfect harmony with the depressed 
central features. Such a change, however, when it is not demanded, 
can never cause the beautifying effect produced by forcing the depressed 
facial features — in segments 1 and 2 — forward, thus bringing into per- 
fect harmony the entire physiognomy. 

This can be verified with any profile view of a typical case — as Fig. 



820 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

863. Fig. 864 is the same face, except that the chin and lower lip have 
been retruded, producing a certain improvement, but not to be com- 
pared with Fig. 865, where the chin and lower lip retain the same 
relative position to the unchangeable area as in Fig. 863, while segments 



Fig. 861. 



Fig. 862. 





1 and 2 have been carried forward, with a result which proves (not 
alone in theory, but in practice) this to be the only true course to bring 
about an harmonious and esthetic adjustment of all the features of the 




physiognomy. Fig. 866 shows the actual difference, which may be 
verified upon trial, between Figs. 863 and 865. 

Fig. 867 will serve to illustrate the common result in practical oper- 
ations of this character. 



UPPER DENTAL AND MAXILLARY RETRUSIONS. 821 

The contouring apparatus (Fig. 895) that is used to accomplish these 
Fig. 865. Fig. 866. 




results is fully described in section VI. of this chapter. With it the 

Fig. 867. 




apical zone of the anterior teeth may be enlarged and advanced to any 



822 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOVBS. 

desired degree ; while the movement and inclination of the crowns are 
under the perfect control of the operator. 

In this operation it will be found in a majority of cases, and espe- 
cially with those which are begun as early as thirteen or fourteen years 
of age, that the entire intermaxillary portion of the upper jaw may be 
carried bodily forward with the roots of the incisors. 

The depressed features of the physiognomy — in segments 1 and 2 
— that are dependent for their contour upon that portion of the max- 
illae are thus brought into perfect harmony with other features of the 
face. 

It is not here implied that there are not many cases of real prog- 
nathous jaw where its retraction, if possible, would produce a most 
desirable result ; nor that such an operation is impossible if recognized 
and treated sufficiently early with properly adjusted apparatus per- 
sistently worn. The body of the lower jaw can certainly be forced back 
to a more posterior position in its relations to the upper, partly by bend- 
ing the rami and necks of the condyles, and partly by absorption of the 
posterior wall of the glenoid fossae. 

The many failures that have attended these operations have been 
largely due to the advanced age of the patients and much to the fact 
that the apparatus is dependent upon the will or caprice of the patient 
for its persistent application. 

On account of the early maturity and ossification of the lower 
maxilla, these operations should be undertaken as early as from five to 
ten years of age. 

The caps fitted to the head and chin should be made to exert a uni- 
form pressure over the surfaces upon which they rest, admit of free 
ventilation, and the whole apparatus when in place should have no 
projecting parts which will interfere with the comfort of the patient at 
night. 

Fine wire gauze answers admirably for the body of caps. It can be 
cut and readily shaped to any contour. First cut a narrow pattern of 
thick paper to accurately fit the zone indicated by the desired border of 
the skull-cap. Duplicate this in thin tin ; solder the free ends together 
and fit to the head to see that it takes the proper position and desired 
flare. Cut the pieces of gauze a little in excess of the required size 
and force it into the rim, where it should be tacked at one point only, 
with soft solder. The adjustment is finally perfected by again fitting it 
to the head and a line drawn along the borders where it is to be com- 
pletely soldered. In constructing the chinpiece, first make a frame of 
German-silver wire, which is then soldered to gauze as shown in Fig. 
868 — the whole to be shaped to produce an even pressure upon the 
chin. 



PHYSIOGNOMY AND THE SAVING OF TEETH. 



823 



Fig. 868. 



The projecting ends of the wire are bent so as to lie close to the face, 
and with sufficient extension to prevent 
the rubber bands pressing into the 
cheeks. The ends are doubled toward 
each other at the proper angle to re- 
ceive the bands. 

Small wire triangles serve to attach 
the rubber bands to the skull-cap, by 
means of flat buttons sewed to the 
gauze. Finally, cover the rim of the 
cap with padded silk ribbon and line 
the chinpiece with some loosely woven 
material, binding the edges with silk. 

The skull-cap is admirably adapted 
also for applying a retruding force to the upper anterior teeth, by 
means of a bar which engages with an encircling wire attached to 
molar anchorages. 




V. The Relations of the Physiognomy to the Saving and 
Extraction of Teeth. 

In its widest scope this subject includes the propriety of saving, and 
on the other hand, the propriety of extracting certain teeth of the 
deciduous as well as the permanent dental arches which in any way 
influence the prevention, the production, or the correction of dento-facial 



Fig. 869. 



Fig. 870. 





irregularities. Two phases of this subject will be here presented. The 
first will be in regard to the saving or the extraction of the upper bicus- 
pids for patients older than fourteen, to correct a dental irregularity ; 
the second will deal with the early extraction of the bicuspids to pre- 
vent an abnormal upper protrusion. 

In the common form of dental irregularity shown by Fig. 869, espe- 
cially if only the model of the upper jaw were the subject of study, it 



824 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



would in all probability be decided to extract the first bicuspids as the 
best course to pursue as a first step toward securing a perfect alignment 
of the dental arch ; and the proceeding would probably be correct as far 
as the upper teeth alone were concerned. And again, if both upper and 
lower models were studied in occlusion and the irregularity of the lower 
arch was — as is usually the case — in correspondence with that of the 
upper, as shown in Fig. 870, the extraction of the lower first bicuspids 
would doubtless, and correctly, be decided upon. This plan of correc- 
tion might even be decided upon after a superficial study of the face of 
the patient, which we may suppose to be similar to that shown in Fig. 
871. Certainly the extraction of the lower first bicuspids, which have 

Fig. 871. 





just begun to erupt, and the retraction of the anterior teeth would 
reduce the apparent protrusion of the lower lip and bring it into more 
perfect harmony with the depressed upper lip. 

Yet when this face is carefully studied from the higher standpoint 
of esthetic development it becomes evident that the chin and lower lip 
are not protruded, in their relations to the malar prominences, the bridge 
of the nose, and the forehead, but that the central features of the physi- 
ognomy are depressed even to a decided retraction of the lower portion 
of the nose ; and that which is really demanded in this case is the ad- 
vancement or forward movement of the entire intermaxillary portion of 
the jaw and incisor teeth ; and further, every tooth in that dental arch 
is necessary for the ultimate retention of the several parts in their 
corrected position. 

In the correction of malformations which demand the protrusion of 
the incisors bodily with the roots and intermaxillary process, the posi- 
tion of the canines, as in this case, will frequently prevent the proper 
attachment and application of apparatus for producing the desired 
effect ; so that it often becomes necessary to first enlarge the dental arch 
and force the crowns into partial alignment by ordinary means, pre- 



PHYSIOGNOMY AND THE SAVING OF TEETH 



825 



paratory to placing the incisors in the grasp of contouring forces. Fig. 
872 shows the position of the teeth in this case in the intermediate 
stage, the anterior teeth crowded into imperfect alignment, and with 
no special facial improvement. (It may be added that at this stage 
the operation, cases of this kind have been considered finished, 



m 



until it was found possible to enlarge the apical arch.) 



Fig. 873. 



Fig. 874. 





Fig. 873 shows correctly the final result, which was accomplished 
with the contouring apparatus described in section VI. It will be 
seen that the incisors are in an upright position and there is now 
ample room for all the teeth, while the remarkable improvement to the 
physiognomy is poorly shown by the face model Fig. 874. 

Another case, that of the upper arch, Fig. 875, if examined alone 

Fig. 87G. 





and compared with the upper of the former case, or Fig. 869, will be 
found very similar. The same crowded condition of the teeth, the same 
lack of sufficient room for the proper eruption of the canines ; and yet 
this is from the model of a case that absolutely demanded the extraction 
of the bicuspids. At fourteen years of age the irregularity presented 
the appearance shown in the illustration Fig. 876, showing the models 



826 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



of the case in occlusion. The patient was placed in charge of a dentist 
who attempted the correction of the irregularity without removal of the 
first bicuspids : Fig. 877 shows the result two years afterward. 

It will be seen that the incisors were forced forward to a decided 
labial inclination, for the purpose of crowding the canines into align- 
ment ; and all the anterior teeth are turned on their axes so as to 
occupy the least possible space. Fig. 878 is from the model of the face 
of the patient at that time. 

That a mistake was made in the plan of treatment pursued is evi- 
denced by the following considerations : First, the protrusion of the 
crowns of the upper anterior teeth produces an unhappy expression 
of the mouth that is equivalent to a deformity, and one that could not 
be remedied in this particular until certain members of the dental arch 
were removed. Second, if it were a case in which the maxillary arch 
was too small, with a depression of the overlying features of the face, 



Fig. 877. 



Fig. 878. 





the decided labial inclination of the teeth could be overcome by an 
enlargement of the apical zone, which would have permitted a slight 
retrusion of the occlusal zone with a partial, if not complete, regulation 
of the dental and facial deformity. But this was not the condition, 
and therefore could not be considered. The third and most effective 
argument is one which should never be overlooked in all cases where 
the crowns flare outward. The conical shape of the teeth permits them 
to stand in perfect alignment though with a decided labial inclination, 
but in this position the interproximal spaces so necessary to the preser- 
vation of the teeth are so completely closed as to cut off the union of 
interproximal gum tissue, which must ultimately result in the resorp- 
tion of the gum and alveolar process and all the dire consequences that 
follow. 

Had the first bicuspids been extracted, many difficulties in the regu- 
lation of the teeth would have been removed ; and what is of far 



PHYSIOGNOMY AND THE SAVING OF TEETH 



827 



greater importance, there would have been a satisfactory result in the 
dental arch and physiognomy. Or even further, had the upper first 
bicuspids been extracted as soon as they erupted, together with the 
deciduous canines, as will be outlined in the second phase of the subject, 
the case would have required little or no other treatment. 

Fig. 879 shows the present position of teeth after regulation, bv re- 
truding the anterior teeth to fill spaces caused by the extraction of the 
bicuspids. Fig. 880 is from a model of the face after treatment. It 



Fig. 879. 



Fig. 880. 





Fig. 881, 



will be seen that the interproximal spaces between the teeth are restored, 
while the retrusion of the anterior teeth allows the lips to fall gracefully 
into proper position. The improvement in the facial aspect of this and 
all other cases cannot be fully shown 
by a plaster model of the face. Fig. 
881 was made from a photograph of 
this patient, taken a few months after 
the completion of treatment. 

There are many instances where the 
early extraction of the bicuspids, as soon 
as they can be reached with the forceps, 
is demanded. 

For example, adult faces with ab- 
normal protruding upper jaws and 
teeth, and with a bulged appearance 
about the lower portion of the nose 
should have been thus treated. The teeth are commonly large, prom- 
inent, and crowded, though not always labially inclined. 

The ordinary upper protrusions which come under this head are 
so common they will require no further explanation or illustration. 

Upper protrusions where the teeth are not labially inclined are not 
quite so common. 




828 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



The alveolar arch is necessarily prominent, though the deformity in 
the main, as in the more common forms of protrusion, is due to the 
large size of the upper maxilla proper, far out of proportion to the 
more delicately chiseled features which it supports and forces into unsym- 
metrical contours. The depressions in which the wings of the nose rest 
are more or less obliterated, as would be occasioned by the sting of a 
bee or an alveolar abscess. The nostrils are broad and open, and the 
end of the nose forced forward and upward [retrousse) by the protrusion 
of the spinous process and cartilaginous septum. The upper lip being 
stretched over its inharmonious frame is shortened so as to cover the 
teeth with difficulty, and in action readily rises to an unpleasant ex- 
posure of the teeth and gums. 

This is an extreme, though not uncommon, condition. Every stage 
from this to perfect harmony characterizes the innumerable varieties of 
a certain type of physiognomy. 

Fig. 882 is from the face model of a young man, eighteen years of 
age, and may be taken as a type of this character of facial deformity. 



Fig. 882. 



Fig. 883. 





Fig 883 shows the teeth in occlusion. The canines and canine emi- 
nences are very prominent, and extend high up under the wings of the 
nose. 

Had this case received the early treatment here advocated, the 
deformity would have been prevented and the almost insurmountable 
difficulties attending its reduction during nearly three years of constant 
treatment altogether avoided. 

Any one who has never attempted to move the roots of the canines 
in a posterior direction for patients older than sixteen cannot begin to 
appreciate the difficulties of such an operation. 

And while the result is quite satisfactory under the circumstances, 
as will be seen by Figs. 884 and 885, the physiognomy is not nearly 



PHYSIOGNOMY AND THE SAVING OF TEETH. 



829 



so perfect esthetically as it would have been had the case received proper 
early treatment. 

The important consideration from a surgical and artistic standpoint 
in nearly all cases of abnormal upper protrusion is : Has not Nature 
been forced to produce these conditions, wholly or in part, to accommo- 
date teeth that were too large for the natural or inherent frame and 
overlying features ? And could we have helped Nature in the early 
years of development, by making it unnecessary for her to produce this 
excessive growth of bone for the development and sustenance of all 
these large teeth? 

The same is true where the protrusion seems to have been caused 
by the inheritance of an inharmoniously large jaw crowded full of 
teeth. 

We certainly cannot reduce the size of the teeth, but we can reduce 
their number, and in so doing reduce the size of the destined maxillary 



Fig. 884. 



Ftg. 885. 





and dental arch. But we must make no mistake. The danger of ad- 
vocating such a principle to those who have given this branch of den- 
tistry little thought is that teeth will be extracted to accommodate an 
overcrowded condition in the arch, with little or no thought of the 
physiognomy, when a careful and properly pursued study of the features 
and their comparison with the parental types will show that in reality 
the dental and maxillary arch should be enlarged, and every tooth re- 
main to induce its natural growth and development. If this has not 
been attained by natural processes, every tooth should certainly remain 
to hold the artificially developed arch in place. 

How are we to study the undeveloped face of a child, every linea- 
ment of which is passing through rapid changes of growth, with a view 
of determining whether or not the dental arch and jaws will be too 
prominent, or that other features will not enlarge to a harmonizing 
proportion ? 



830 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

A most wonderful provision of Nature in dentition causes the full- 
sized crowns of teeth to erupt, as regards time, somewhat in proportion 
to the natural growth and enlargement of the jaws. And even when 
they do not erupt earlier than is normal, or when their natural eruption 
is not interfered with by the premature extraction of the deciduous 
teeth, they are usually obliged to take an irregular position or attitude 
at first, and await the growth of the jaw which permits them to become 
regular. 

It is perhaps a safe general rule to never extract a permanent tooth 
for the purpose alone of correcting a dental irregularity, unless the jaw 
has ceased growing ; and never then unless it is shown by a careful study 
of the position of the teeth — their relation and occlusion — that the den- 
tal arch should not be expanded ; or by a study of the physiognomy, 
that the alveolo-dental arch should not be enlarged. 

In a study of the relations of the teeth, the jaws, and the physiog- 
nomy of a child with the view of determining the advisability of extrac- 
tion to correct or prevent the ultimate production of a facial deformity 
or marked imperfection of the features, it may become necessary to 
study the physiognomies of both parents and possibly other members 
of the family, to correctly determine the influence of inheritance. 

In this comparison of temperament, physical frame, features, and 
teeth, it may require no more than a glance to furnish all the data that 
will be of practical use. 

Usually but one parent accompanies the little patient, and a study 
of that one physiognomy may be a sufficient guide ; if not, other mem- 
bers of the family should be seen. 

If there be a marked difference in the parents it may not be difficult 
to determine from which the child has inherited the teeth, by the 
peculiar shape and size of the incisors alone. But in regard to the 
maxillae in an undeveloped condition there will be more difficulty, 
though it is well to remember that the deciduous teeth are rarely irregu- 
lar or disproportionate in size to the frame and facial features. If, there- 
fore, there be a more than natural difference in the size of the permanent 
and deciduous teeth it will indicate union of inharmonious types. 

In this connection it must not be forgotten that the crowns of the per- 
manent incisors are almost invariably far too large for their undevel- 
oped surroundings. The apparently disproportionate size of the cen- 
tral incisors to that of the jaw is a subject of frequent and anxious 
parental comment. If the occlusion of the incisor teeth be far from a 
normal type in their anterior relations, and the same condition exists 
with either parent, it is an indication of what the child will become if 
unaided by dental skill, especially if a similarity be noted in other 
particulars. 



PHYSIOGNOMY AND THE SAVING OF TEETH. 831 

With differences in temperament, compare general shape and size of 
the eyes, brows, ears, and teeth. 

Other features are so subject to change in the processes of natural 
growth and development that they cannot be relied upon to furnish 
legitimate data. For instance, the nose may change in a few years 
of late youthful development from one originally small and short — 
and over the nasal bones decidedly depressed — to a form different in 
every particular. 

When neither parent presents the same unsymmetrical relations that 
promise to prevail in the child, the cause may be a union of the large 
teeth of one parent with the small jaws of the other. 

When the teeth of the parents are decidedly dissimilar in size, it 
may be possible, as before stated, to determine with certainty from 
which parent the teeth of the child are inherited, and when the teeth 
and jaws of the other parent are small and other features are similar 
to those of the child, it indicates a union of undiluted types. 

All these things are of the utmost importance in determining the 
impropriety of extracting certain teeth to reduce an apparent abnormal 
protrusion, which may in time become symmetrical in its relation by 
the natural growth of the jaws and other features ; and also the equally 
culpable error of saving teeth, or the failure to extract teeth, whose 
very presence in the arch obliges Nature to reproduce a parental 
deformity, or produce an acquired deformity, by an effort to sustain the 
large teeth of one parent in conjunction with the small jaws of the 
other. 

For a child with an abnormal upper protrusion similar to Figs. 886 
and 887, with teeth prominent and crowded in an arch which does not 
Fig. 886. Fig. 887. 




admit of correcting by a lateral expansion, extract the first bicuspids as 
early as possible, even before their eruption is completed, together with 
the deciduous canines — unless it be one of those very rare instances 
where the first permanent molars cannot be saved. 



832 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



The same is true of the lower, when there is reason to believe 
there will be a disproportionate over-development of the lower dental 
arch. 

In the ordinary course of eruption the development and eruption of 
the permanent canines are doubtless more influential than those of other 
teeth in emphasizing an anterior protrusion of the central features of 
the physiognomy. 

In the course of their eruption they are obliged to crowd into align- 
ment along the mesial surfaces of the roots and crowns of the first 



Fig. 888. 



Fig. 889. 





Fig. 890. 



bicuspids — which at this time represent the immovable bases of the 
arch — with the result that the incisive and intermaxillary portion of 
the arch is forced forward to a more pronounced position. This move- 
ment has been shown to be not impossible or difficult of attainment by 
artificial force, even much later in life. 

With the first bicuspids and deciduous canines removed sufficiently 
early there are numberless instances when the arch, anterior to the 

second bicuspids, would be diminished the 
width of a bicuspid, without resort to arti 1 - 
ficial means. 

By the exertion of a slight traction force 
from an occipital base of anchorage the 
sockets of the temporary canines will be 
closed by the permanent laterals, and the 
permanent canines in the course of their 
eruption will be deflected into the alveoli 
of the extracted bicuspids. 

Figs. 888 and 889 represent one case out 
of many under treatment by this method, 
though not all by the occipital method. 
Fig. 890 shows the position of the teeth after about two months 




THE CONTOURING APPARATUS. 833 

of traction force from molar anchorages ; the protrusion not being so 
pronounced as to demand the use of the skull-cap. 

It will be seen by the canine eminences — though far better shown 
upon the model itself — that the position of the canine crowns is imme- 
diately over the former alveoli of the first bicuspids. As they continue 
to grow downward in this somewhat open channel, their roots, which 
are not at present developed, will grow upward, the teeth in their en- 
tirety finally taking a position and inclination similar to that of the 
bicuspids which they replace, and considerably posterior to that which 
they were otherwise destined to occupy. 

The patient, nine years of age, had the teeth, eyes, ears, and general 
temperament of the father, whose upper arch was abnormally protruded 
in a similar manner, which was the raison d'etre for dental aid. 

Had the father's teeth been in proper relative and symmetrical 
position, and similar to the son's in other particulars w T hich could be 
legitimately used as data, it would have been an argument in favor 
of non-extraction with the expectation of other treatment later ; but 
it should not have been passed upon without seeing the mother. Had 
the mother's teeth been found small and the general physical features 
cast in a more delicate mould than her husband's, investigations along 
other lines w r ould have been required with the view of determining 
if the child had not the large teeth of the father and small jaAvs of the 
mother; in which case extraction would also have been indicated. 

VI. The Contouring Apparatus. 

The limited area upon which force can be applied to a tooth, com- 
pared with that portion covered by the gum and imbedded in a bony 
socket, has made it next to impossible, with all ordinary methods, to 
move the apex of the root in the direction of the applied force ; nor 
could this ever be accomplished w T ith force exerted in the usual way at 
one point upon the crown, however near the margin of the gum it may 
be applied, for the opposing margin of the alveolar socket must receive 
the greater portion of this direct force, and in proportion to its resist- 
ance it will become a fulcrum exerting a tendency to move the apex of 
the root in the opposite direction. 

But if in the construction of the apparatus a static fulcrum is created 
independent of the alveolar process at a point near the occluding portion 
of the crown, while the power is applied at a point as far upon the root 
as the mechanical and other opportunities of the case will permit, the 
apparatus becomes a lever of the third kind, the power being directed 
to a movement of the entire root in the direction of the applied force. 

This proposition is made plain by reference to diagrams. In Fig. 
891 let A be a point upon a central incisor at wdiich force is applied in 

53 



834 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 



the direction indicated by the arrow, then will the opposing wall, B, of 
the alveolar socket near its margin receive nearly all of the direct force ; 
and in proportion to its resistance will there be a tendency to move the 
root in the opposite direction. This will also hold good even if the 
force be applied at A, Fig. 892, or as far upon the root as may be per- 
mitted by attaching a rigid upright bar, c, to the anterior surface of the 





crown ; the only difference being that the direct force is distributed 
over a greater area. But if, as in Fig. 893, to the lower end of c a 
traction wire or bar, F, is attached and if the mechanical principles of 
the machine be further enforced by uniting its posterior attachment to 
the anchorage of the power bar, P, the anchorage force will be materially 
neutralized and an independent static fulcrum at D created. The appa- 
ratus now will distribute its force over the entire root, and give com- 
plete direction and control of whatever power is put into it. The 

Fig. 893. 




entire tooth may be carried forward bodily or either end may be made 
to move the more rapidly. The force thus directed to the ends of the 
roots will have an increased tendency to move the more or less yielding 
bone in which they are imbedded. 

For practical illustrations of what has been accomplished by an 
apparatus of this kind see cases described in sections L, IV., and V. of 
this chapter. 

The contouring apparatus is made entirely of German silver, with 
the exception of the nuts, which are of nickel. German silver is pre- 
ferred, not because it is cheaper than gold and platinum, but because it 



THE CONTOURING APPARATUS. 835 

possesses certain qualities which render it adapted for the purpose to 
which it is applied. 

In making the banding material for this apparatus, thoroughly an- 
neal a piece of wire No. 13 and pass it through the rollers — with an 
occasional re-annealing — until it is reduced in thickness to Nos. 35 and 
38 (or 0.004 and 0.0056 of an inch). 1 This will give bands about J and 
T 3 g- of an inch wide. Use the thinner material for the anterior teeth 
and the thicker for the anchorage appliance. Before using, it should be 
wound into rolls and brought to an even red heat, held there for ten 
minutes, then allowed to cool slowly. This will ensure perfect softness 
and adaptability. 

In taking the measurements for the bands, cut from the material 
the proper length, and, holding the ends of the loop between thumb and 
finger, pass it over the tooth to be fitted. When in place bend the ends 
sharply at right angles and finally, grasping the two ends in the pliers, 
draw the band firmly around the tooth. The bands for the anterior 
teeth should extend at this time sufficiently beneath the approximal bor- 
ders of the gum to assure complete extension to the labio- and linguo- 
gingival borders. The approximal extension should be cut down to the 
gingival border of the enamel in the final finishing of the apparatus. 

After the bands are soldered carefully, fit and burnish them to the 
teeth. In order to obtain perfect adaptation it often becomes necessary 
to contour them slightly with the proper pliers. The joint which pro- 
jects on the anterior surface of the bands for the anterior teeth should 
be placed at one side of the middle to allow the upright bar c, Fig. 893, 
to rest exactly along the median line. 

When the teeth are so crowded together that the banding material 
cannot be passed freely between them they should first be separated 
with waxed tape. It is to be preferred to rubber because sufficient 
space is obtained in twenty-four hours with little or no discomfort to 
the patient beyond the general soreness of the teeth, which must always 
follow the preliminary steps of a regulating operation. These tapes 
are allowed to remain between the teeth — renewing them each day — till 
the final attachment of the apparatus. 

The first appliance to be described is that designed for moving the 
roots of the upper incisors forward. 

Before it is possible to apply the contouring force it is frequently 
necessary to first move the crowns of very irregular teeth into align- 
ment somewhat — and even to rotate them — so as to bring them into a 
position to be properly grasped by the power bar of the apparatus. 
(See Fig. 872, with description.) 

1 In this description it will be understood that German silver is the metal indicated 
and Brown & Sharp' s gauge that by which thicknesses are measured. 



836 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

When the bands have been fitted as described above, they should be 
placed upon the four incisors and a plaster impression taken of the 
labial surfaces of the bands, teeth, and adjoining gum. For a tray to 
carry the plaster to place use a thin piece of lead cut the proper 
size. 

After the impression is removed, carefully remove the bands and 
place them in their respective positions on the impression ; the joints 
of the bands will serve to guide them to place. This when filled with 
Teague's or other investing material will give a model with the bands 
in position, to which may be fitted and soldered the upright bars. 

The upright bars are made of No. 14 wire, bent to fit the anterior 
face of the band and tooth along the median line of its axis, and also 
the gum to about ^ of an inch above its margin. In soldering them to 
the bands, completely fill the V-shaped spaces on either side the upright 
bars, to give sufficient rigidity and finish to the appliance. After they 
have been soldered and removed from the model they are further finished 
by filing the bars flat on the sides which lie next to the gum, tapering 
them to one-half their diameters at the upper ends. It is against this 
surface that the power bar, p, is to rest, as shown in Fig. 893. The 
upright bar may also be flattened somewhat over the face of the tooth, 
but not at the point where it leaves the band for the gum, as full 
strength and rigidity are required here. (In Fig. 893 the engraver has 
made the upright bar appear far too light at this point — marked c — for 
practical use in sustaining the great force of the power bar at B.) 

The bars having been cut off even with the occluding ends of the 
teeth, and properly rounded and polished, the small transverse grooves, 
D, may be cut just above the ends to receive the fulcrum wire, f, No. 
24 gauge, which is much smaller than shown in Fig. 893. 

In constructing the anchorage portion of the apparatus to be attached 
to the posterior teeth too much care cannot be observed in order that 
the several parts perform the work assigned to them and the greater 
portion of force be neutralized at points of anchorage. 

When the second molars have fully erupted, band the first and 
second molars — otherwise the second bicuspids and first molars — and 
sometimes all three teeth. Where it becomes advisable to apply this 
particular form of force before the eruption of the second bicuspids, 
the second deciduous and first permanent molars will answer for the 
purpose. 

The banding material should be as wide as the tooth will permit, 
and in thickness from Nos. 36 to 35 (or 0.005 to 0.0055 of an inch). 
When the bands have been made as described and perfectly fitted, place 
them in the positions they are to occupy and take a plaster impression 
— one side at a time — allowing the plaster to barely cover the bands,, 



THE CONTOURING APPARATUS. 837 

but sufficiently extensive to show on the model the bicuspids and 
canines, for reasons that will become obvious. 

After removal, replace the bands accurately in their positions in the 
impression, and fill as before with Teague's or any good investing 
material. 

This material will give a model that will hold the bands in exact 
relative position while they are being soldered, and one also that is suf- 
ficiently extensive to enable the placing and soldering of the tubes in 
proper position and direction — a thing of the utmost importance. 

In selecting the tubes the smaller should loosely fit the threaded end 
of No. 20 wire, which is the size to use for the fulcrum wire, F. The 
size of the larger tube should be governed by the size of the power bar, 
i. e. when the jaw is large with fully developed teeth, or when the dis- 
tance is considerable from anchorage appliances to the upright bars on 
the anterior teeth, the size of the power bar, p, should be No. 14. It 
should rarely be smaller than No. 15, though when the operation is 
attempted for very young children No. 16 will answer the purpose. 
But the ordinary German -silver wire of the shops of these sizes will 
not do. It must be specially prepared in order to withstand, without 
bending, the great force exerted upon a bent bow or bar. All wire for 
power bars should be drawn, without annealing, from No. 6, and be 
nearly as rigid as tempered steel. In the selection of tubes the larger 
should loosely fit the threaded end of the power bar, and be \ to f of 
an inch long. 

An important feature is the position of the power-bar tubes. They 
should be so placed and soldered to the anchorage bands that the power 
bar — when placed in the tubes — will ex- 
tend from it in a straight line to the ca- Fig. 894. 
nines, where it bends over to engage with 
the upright bars, c. (See Fig. 893.) If 
this precaution be not taken, but instead the 
power tubes are soldered in the ordinary 
way, in contact with the buccal surfaces of 
the bands, the power bow, in most instances, 
will require to commence its encircling bend 
immediately upon emerging from the tubes, 
with a decided weakening of its rigidity and 
possible failure. 

In order to obtain the proper position 
it will often be advisable to rest the poste- 
rior end of the larger tube upon that of 

the smaller, as shown in Figs. 894 and 895. All projecting portions 
that are liable to irritate the mouth should be rounded and polished^ 




838 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

In soldering tubes to place use a slightly lower grade of silver solder 
than that used to join the bands. Use sufficient to thoroughly unite all 
the joints, and fill all V-shaped spaces, being careful to turn the joints 
of the tubes toward the bands that they may be closed. Thoroughly 
unite the approximal surfaces of the bands and reinforce the lingual V 
with an extra piece. (See Fig. 894.) 

In finishing the apparatus, the soldered parts should be boiled in a solu- 
tion of sulfuric acid to remove the borax and oxids. After being neu- 
tralized and brushed they are now ready for the trial fitting to the mouth. 

In this operation the bands should be perfectly fitted to the position 

Fig. 895. 




Protrusion apparatus. 

they are to occupy — the upright bars readjusted, if necessary, and all 
surplus material cut away— sharp and rough surfaces smoothed and 
polished, and the gingival and occluding edges of the bands carefully 
burnished to the teeth. 

In constructing the power bar the anchorage attachments should be 
placed upon a plaster model of the teeth, in order to accurately deter- 
mine its length and the lengths of its threaded ends, then properly 
shaped to the gum over which it is to rest. It should be flattened in 
the rollers to about one-half its diameter along that portion which lies 
in front of the bicuspids. In this operation it may become necessary 
to roll the bar so that the bent bow is flaring, to fit the gums against 
which it nearly rests, and to engage perfectly with the upright bars — 
especially if the incisors are labially inclined. 

When the apparatus is polished and heavily gold-plated it is ready 
for the final cementing to the teeth. Brush the teeth with pumice stone, 



THE CONTOURING APPARATUS. 839 

place a napkin in the mouth, and dry the teeth and surrounding gum 
with spunk. Pack it around the teeth, where it is held firmly in posi- 
tion while the cement is being prepared and placed in the bands by an 
assistant. See that all material used in polishing is removed from the 
inner surface of the bands, and the surface scraped or scratched with a 
sharp excavator. 

The cement should be mixed thoroughly, but rapidly, to the con- 
sistence of thick cream, and scraped from the spatula along the upper 
and inner edges of the bands. 

When each part of the appliance is ready, force it quickly and firmly 
to its position ; its final adjustment being perfected by the use of the 
mallet on a large oval plugger resting upon the soldered parts. 

After the anchorage attachments have been cemented in place, make 
an appointment for the next day to attach the remainder of the appa- 
ratus, in order to allow the cement to become perfectly hardened, that 
the bands may not be dislodged, or even slightly started, by the strain 
to which they are subjected in the final adjustment of the power bar. 

Another way is to adjust the anchorage attachments to the ends of 
the power bar — out of the mouth — after the parts have been perfected, 
shaped, and fitted — and cement the whole to place in this condition. 
By this method the whole apparatus can be attached to the teeth at one 
sitting. 

On account of the intense rigidity of the power bar it is important 
that when it is in place on the teeth the threaded ends should lie within 
their respective anchorage tubes without exerting the slightest force in 
any direction until it is applied, as intended, by the power of the screws ; 
therefore great care should be observed in giving to it the proper shape, 
by bending as accurately as possible upon the plaster model, and after- 
ward by a trial fitting in the mouth before cementing the anchorage 
bands. 

With the anchorage attachments and power bar in position the bands 
are to be cemented to the anterior teeth. As each band is carried to its 
place, it should be seen that the flattened surface of the upright bar is 
pressed down firmly upon the power bar, so that an even force will be 
given to each of the teeth when power is applied — it being presupposed 
that in the trial fitting of the parts the power bar was shaped so as to 
engage perfectly with the upright bars — the free ends of the latter ex- 
tending slightly above it. 

The same kind of apparatus may be employed upon the lower in- 
cisors with perfect success, though there will not be the same tendency 
to carry the entire alveolar ridge forward with the roots as on the 
upper ; the change being largely by a metamorphosis of alveolar tissue. 

An apparatus for contruding the roots of the anterior teeth is con- 



840 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS. 

structed in a very similar manner. The direction of the two forces 
being reversed, it becomes necessary, however, to make certain import- 
ant variations. The power bar (p, Fig. 896) now exerting a traction 
force, No. 16 will be found sufficiently large for all purposes. It is 
not flattened, but rests in grooves cut in the anterior surfaces of the 

Fig. 896. 




upright bars, B. The power-bar tubes should be soldered closely to the 
anchorage bands so that the nuts which now work at the posterior ends 
of the bar will not irritate the mucous membrane of the cheek. The 
fulcrum bar, F, exerting in this apparatus a jack-screw force, should be 



Fig. 89 




No. 16. It is flattened along its middle portion to engage with the 
occluding ends of the upright bars at D, provision being made for the 
purpose in the construction. 

The power of the two forces being so great upon the upright bars, 
with a tendency to lift the occluding ends from their attachments, and 
thus allow the free ends to press into the gum, it is important with this 
apparatus that the occluding end attachments be reinforced by soldering 



THE CONTOURING APPARATUS. 841 

to the bands an extra piece of banding material that shall extend from 
the labial face over the occluding end of the tooth to the lingual portion 
(shown in Fig. 897). 

After the joint of the band has been soldered, the reinforcing piece, 
of sufficient length for the purpose, should first be soldered to the labial 
face alongside of the joint; then the band is perfectly fitted to the 
natural tooth — the extra piece being bent over and burnished to its 
position on the labial surface, and the position of its end distinctly 
marked upon the band, to serve as a guide to soldering. 

When the hoods are completed in this way and finally all placed on 
the tooth and perfectly fitted, an impression should be taken for fitting 
and soldering the upright bars as described for the protrusion apparatus. 



INDEX. 



ABSCESS, alveolar, in deciduous teeth, 
680 
chronic, with fistulous opening, 497 

treatment of, 495 
dento-alveolar, 479 
opening of, 494 
treatment of, 496 
Acid conditions of the oral fluids, effect of, 

191 
After-treatment of pulp exposure, 415 
Age, relation of, to pyorrhea, 527 
Air, admixture of, with nitrous oxid, 631 
Albumin, action of mercuric chlorid on, 

435 
Albuminous food, use of, in pyorrhea, 530 
Alcohol, use of, in pulp treatment, 426 
Alkalies, action of, on dental pulp, 434 
use of, in treatment of sensitive dentin, 
194 
Alkaline waters, use of, in pyorrhea, 530 
Alkalithia, 530 
Alloy and cement fillings, 367 
Alloys, aging of, 253, 308 
Alum, use of, in pulp devitalization, 441 
Aluminum amalgam, 314 
Alveolar abscess, 479 

at bifurcation of roots, 499 
brain infection from, 586 
causes, 479 
chronic, 486 
clinical history, 485 
complications of, 500 
diagnosis and prognosis, 487 
pathology and morbid anatomy, 480 
treatment, 489 
process, absorption of, in pyorrhea, 524 
accidents to, after extraction, 612 
anatomy of, 577 
necrosis of, 637 
resorption of, 578 
ridge, bending of, in regulating teeth, 
698 
Alveoli, enlargement of, from regulating 

appliances, 701 
Alveolo-dental membrane, 91, 135 
Amalgam as a cavity lining, 258 
and gold fillings, 354 
first use of, as filling material, 305 
"flow" of, 308 
methods of use, 315 
nature and properties of, 306 
objections to, 255 
proportions of ingredients, 252 
use of, in deciduous teeth, 675 
wafering of, 677 
war, 305 
washing of, 314 



Amalgams as filling materials, 255 
classification of, 312 
binary, 312 
ternary, 313 
quaternary, 314 
combination of, 361 
composition of, 252 
contraction and expansion of, 307 
edge strength of, 310 
Ambidexteritv, advantages of, 595 
Ameloblasts, 62, 100 
Ammonia in pulp exposure, 667, 679 
Amyloid, 437 

Anchor bands for regulating, 706 
Anchorages in approximal cavities, 230, 

234, 237 
Anesthesia by cataphoresis, 194 
complete, symptoms of, 633 
general, 212 
Anesthetics, general, examination of 
patients, 618 
tooth extraction under, 617 
local, and tooth extraction, 639 
use of, in planting teeth, 657 
Angles, avoidance of, in shaping cavities, 

220 
Angle's regulating appliances, 703, 711 

retaining appliance, 742 
Annealing tray, electric, 275 
Anodes for cataphoresis, 205 
Antisepsis as related to the plantation of 
teeth, 164 
in dentistry, 157 - 
in pulp treatment, 458 
Antiseptic dressing for exposed pulps, 411 
forceps, 565 
mouth-wash, 458, 514 
Antiseptics as sterilizers, 440 

in pulp treatment, 433 
Antral empyema, 501 
Antrum, drainage of, 502 

perforation of, in implanting teeth, 655 
Apical pericementitis, treatment of, 476 
region, mode of entrance to, 475, 492 
Appliances used in examinations, 174 
Approximal cavities, filling of, 286 
preparation of, 229 
surfaces, examination of, for caries, 177 
treatment of, 262 
in regulating, 737 
of cavities on, 184 
Appro ximo-incisal cavity, 234 
Arch, dental, 18 
normal, 684 
saddle-shaped, 784 
semi-V-shaped, 758 
spreading of, 754 

843 



844 



INDEX. 



Arch, dental, V-shaped, 757 

Areas, eroded, 304 

Aristol as an antiseptic, 188, 435 

Arsenic, action of, on dental pulp, 422 
use of, in deciduous teeth, 679 

Arsenous acid in pulp devitalization, 421 

Arterial hemorrhage, treatment of, 614 

Arthur's method of filling, 262 

Articular gout, 521 

Asbestos felt, use of, with silver nitrate, 
668 

Asepsis, importance of, in planting teeth, 
656 

Asphyxia, avoidance of, in nitrous oxid 
anesthesia, 625, 631 

Assistant, necessity for, in nitrous oxid ad- 
ministration, 632 

Automatic mallets, 279 

BACTERIA of pyorrhea, 525 
Balsamo del deserto, 438 
in temporary teeth, 503 
Band matrices, 291 
Bands, regulating, 714, 719 
Basal layer of Weil, 87, 128 

temperaments, 51 
Basic zinc cements, 334 
Battery cells, arrangement of, for electrical 

osmosis, 198 
Benzoyl pseudo-tropin, 642 
Bibulous paper, use of, in combination fill- 
ings, 356 
Bicuspids, early extraction of, 827 
extraction of, 603, 606 
microscopical anatomy of, 32 
pulp chambers of, 447, 448, 450 
Binary amalgams, 312 
Binoxid of tin, use of, in polishing teeth, 

181 
Bit, regulating, 767 
Bite, jumping~of, 770, 812 

raising of, 793 
Black's studies of amalgams, 253 
Bleaching agents, 540 

powder, care in selection of, 547 
teeth suitable for, 542 
Blennorrhea alveolaris, 509 
Blind abscess, 495 
Blood as an antiseptic, 656 
Blood-poisoning, danger to operator from, 

164 
Bonwill's method of amalgam filling, 320 
Bows for regulating, 739, 765 
Brain, infection of, from suppurating tooth, 

586 
Breathing, management of, in nitrous oxid 

anesthesia, 632 
Broach, employment of, as pulp extractor, 

453 
Bromin as an antiseptic, 434 
Brown bands of Retzius, 107 
Bryan's regulating method, 799 
Buccal cavities, filling of, 283 

preparation of, 226 
Burnishers, oiling of, 360 
Burs, forms of, 216 

for pulp-canal treatment, 452 



CACHEXIA, influence of, in alveolar 
abscess, 486 
Calcic inflammation, 509 
Calcific changes in dental pulp, 417 
Calcification, process of, 73 
Calcium salts, presence of, in stellate retic- 
ulum, 66, 83 
Calco-globulin, 73 
Calco-spherites, 70, 73 
Callahan's method of pulp treatment, 462 
Camphor in treatment of nausea, 248 
Canal fillings, essential properties of, 436 

treatment, instruments for, 452 
Candy, effects of, on the teeth, 681 
Canines, eruption of, 690 

extraction of. 602 

macroscopical anatomy of, 28 

prominent, 744 

pulp chambers of, 447 

rotation of, 750 
Caoutchouc as a separator, 187 
Cap-and-bit regulating appliance, 767 
Capillary hemorrhage, treatment of, 614 
Capping pulps, methods of, 411 
Caps, for treatment of prognathism, 822 

placing of, over exposed pulp, 412 

swaged, for regulating, 704, 714 
Carbolic acid as an anesthetic, 209 
in pulp exposure, 409 
in pulp treatment, 421 
Caries, differentiation of, from alveolar ab- 
scess, 488 

due to irregularities, 700 

self-limited, 219 
Cataphoresis, dentinal anesthesia by, 194 

technique of, 203 
Cataphoric bleaching methods, 555 
Cathode electrode for cataphoresis, 206 
Caustic pyrozone, 550 
Cavities, approximal, filling of, 671 

classification of, 223 

enlargement of, for pulp treatment, 459 

finishing margins of, 223 

occlusal, filling of, 669 

preparation of, 215 

varnishing of, 360 
Cavitine, 549 

as a cavity lining, 258 
Cavity lining, 257 

simple, conversion of, into compound, 
230 

walls, fracture of, 302 
Cement and alloy fillings, 367 

and amalgam fillings, 351 

and gold fillings, 353 

amalgam, and gold fillings, 358 

fillings, burnishing of, 360 

fluids, instability of, 338 

lining for amalgam fillings, 323 

paraffin coating for, 675 
Cemented inlays, 369 
Cementoblasts, 143 
Cemento-periostitis, 509 
Cements as filling materials, 255 

use of, in separations, 187 
Cementum, 132 

calcification of, 86 



INDEX. 



845 



Cervical margins, exposure of, 187 
Chair, dental, requisites for, 594 

form of, for nitrous oxid administration, 
631 
Chart record of examinations, 178 
Children, treatment of, in the dental office, 

666, 669 
Children's teeth, operations on, 502 
Chin, malpositions of, 810 
Chisels, use of, in opening cavities, 216 
Chloric! of silver cell battery for catapho- 

resis, 202 
Chlorin, action of, on metals, 517 

as a bleaching agent, 541 

as a sterilizer, 434 
Chloroform as an anesthetic, 213 
Chloro-percha as a root-tilling, 438, 446 
Chromic acid as an anesthetic, 212 
Clamps, rubber dam, 244 
Coagulants in pulp treatment, 434 
Coagulation as a chemical process, 435 
Cobalt as a devitalizing agent, 424 
Cocain, antidotes for, 643 

as a local anesthetic, 639 

cataphoric use of, 195, 203 

hypodermatic injection of, 640 

in pulp treatment, 424 

physiological effects of, 640 

relief of hypersensitiveness by, 188, 193 

Schleich's solution, 642 

toxic effects of, 643 
Cocoa butter as a lubricant, 361 
Coffin regulating appliances, 707 

spring plate, 742 
Cold as a test of pulp exposure, 406 
Color, stability of, in amalgams, 255 
Combination fillings, 345 

finishing of, 357 
Compound cavities, combination tilling of, 
348 
tilling of, 287 
preparation of, 233 
Cone, evolution of tooth forms from, 17 
Contact, points of, in teeth, 263 
Contour fillings, 261 
Contouring apparatus, Case's, 821, 833 
Contraction of amalgams, 307 
Controllers for cataphoresis, 199, 202 
Copper amalgam, process of making, 312 

staining of teeth by, 558 
Corundum wheels, use of, in regulating, 

736 
Cotton as a canal filling, 464 

as a root filling, 437 

as a separator, 186 

method, of introduction into root canals, 
465 
Counter-irritation in pulp exposure, 410 
Crown, restoration of, with amalgam, 324 

structure, conservation of, in root filling, 
458 
Crowns, artificial, on natural roots, 655 
Crver's studies of the maxillary sinus, 501 
Crystal gold. 273 

mat gold, 274 
Cunningham's regulating method, 800 
Cusp, supplementary, on first molar, 227 



Cusps, malocclusion of, 788 
Custer's annealing tray, 275 
Cutter's regulating appliance, 792 

DAVEXPORTS regulating appliance, 
793 
Decay, removal of, in preparation of cavi- 
ties, 217 
Deciduous teeth, indications for extraction 
of, 561, 689 
macroscopic anatomy of, 48 
management of, 663 
Deformities, inheritance of, 805 
Dental arch, tvpal forms of, 18 
follicle, 71 
formula of man, 22 
groove, 55 
pulp, capping of, 411 

conservative treatment of, 401 
devitalization of, 421 
embryology of, 87 
exposure of, 403 
sensitivity of, 402 
ridge, formation of, 55 
sacculus, 41 

tissue, structure of, 53, 96 
Dentate fissure burs, 452 
Dentin, analysis of, 121 
calcification of, 74 
carious, removal of, in preparation of 

cavities, 218 
discoloration of, 425 
germ, formation of, 60 
hypersensitive, 189 
treatment of, 193 
infection of, 457 
matrix, 77, 121 
normal sensitivity of, 190 
secondary, 414, 417 
structural elements of, 120 
Dentinal anesthesia bv chemical agents, 
207 
papilla, embryology of, 70 
tubuli, fibrillar structure of, 192 
Dentition, pathological, 663 
Development of dental tissues, 53 

of jaws, 53, 94 
Devitalizing fiber, 679 
paste, 421, 423, 678 
Diet, relation of, to pyorrhea, 527 
Dietetic treatment of pyorrhea, 530 
Digitalis as a hemostatic, 617 
Dioxid bleaching methods, 550 
Disinfectants in pulp treatment, 433 
Dissection, necessitv for, 576 
Distal cavities, filling of, 287, 294 
occlusion of, 685 
preparation of, 229, 231 
Disto-incisal cavities, filling of, 288 
Disto-labial cavities, filling of, 287 

preparation of, 233 
Disto-lingual cavities, filling of, 288 

preparation of, 233 
Disto-occlusal cavities, filling of, 290 

preparation of, 237 
Donaldson's pulp-canal cleaners, 454 
Drag-screw, use of, in regulating, 749 



846 



INDEX. 



Drill, safety, for pulp extraction, 455 
Dynamo, use of, for cataphoresis, 203 
Dyspepsia due to irregularities, 700 

EBUKNATION, 190 
Edge, restoration of, with gold, 286 
Edge strength of amalgams, 253 

of fillings, 345 
Electric mouth-lamp, 176, 177 
Electrical osmosis, 194 
Electricity, cataphoric action of, 194 

general principles of, 196 
Electrodes for cataphoresis, 266 
Electro-magnetic mallet, 279 
Electrozone, 434 
Elevators, 574 

for tooth extraction, 543 

non-use of, under anesthesia, 635 
Embryology of dental tissues, 53 
Embryonic mucous membrane, 54 
Enamel, analysis of, 98 

calcification of, 82 

cleavage of, 221 

" drops," 84 

injury to, by regulating appliances, 702 

organ, formation of, 60, 62 

structural elements of, 96 
Engine burs, use of, in opening cavities, 
215 
on children's teeth, 676 
Eroded areas, 304 

Essential oils as antiseptics, 434, 436 
Ether, administration of, for anesthesia, 212 

mode of administration, 619 

use of, in tooth extraction, 618 
Ethyl chlorid as a local anesthetic, 639 
Eucain as a local anesthetic, 644 
Examinations, appliances used in, 174 

record of, 178 

technique of, 177 
Excavators, forms of, 218, 232 
Explorers, use of, in examinations, 175 
Expression, features of, 659 
Extracting, art of, 635 
Extraction, after-treatment of, 611, 637 

mode of, under anesthesia, 634 

FACE, esthetic development of, 824 
measurements of, 683 
Face-piece, use of, in nitrous oxid adminis- 
tration, 631 
Facial contour, influence of the teeth on, 
805 
deformities, correction of, 812 
expression, change of, by movement of 

teeth, 809 
profile, ideal, 683 
Facing amalgam, 323 
Faught's electric heater, for gutta-percha, 

329 
Felt tin, 296 
Fibers of Tomes, 127 
Filling materials for deciduous teeth, 669 
amalgam, 675 

lack of edge strength, 345 
gutta-percha, 669 
selection of, 249, 267 



Filling materials, table showing character- 
istics, 370 
zinc phosphate cement, 672 
Fillings, amalgam and gold, 354 

amalgams of different quality, 367 

cement, amalgam, and gold, 358 
and alloy, 367 
and amalgam, 351 
and gold, 353 

combination, 345 

crvstal mat and other forms of gold, 361 

finishing of, 297, 325, 335 

gold and tin, 365 

gutta-percha and amalgam, 361 
and cement, 359 
and gold, 361 

non-cohesive and cohesive gold, 363 

removal of, preparatory to bleaching, 546 

repair of, 301 

temporary, 213 

tin and gold, 367 

tin -gold, 365 

zinc phosphate and amalgam, 346 
Finishing bur for cavity margins, 222 
Firth's method of pulp mummification, 441 
Fistula, treatment of, 497 
Fistulse of alveolar abscess, 482 
Fistulous abscess, treatment of, 492 
Flagg's formula for amalgam, 313 

gutta-percha softener, 328 
Fletcher's carbolized resin, 667, 674 

method of mixing amalgams, 319 
Floss silk, use of, in deciduous teeth, 681 

in examinations, 179 
"Flow" of amalgams, 308 
Force, application of, in filling operations, 
276 

constant, 706 

intermittent, 706 
Forceps, antiseptic, 564 

best forms of, 564 

extracting, manner of use, 597 

for extracting lower teeth, 572 

forms of, for regulating, 799 

knuckle-joint, 566 

necessary forms of, 635 

nickel-plating of, 636 

pharyngeal, use of, 577 
Formalin as an antiseptic, 469, 471 

in pulp treatment, 422, 435 
Furnaces for fusing porcelain, 393 

GALVANIC current, application of, to 
sensitive dentin, 200 
Gangrenous pulps, micro-organisms in, 430 
Gauge, plate, 704 
German-silver matrix, 349 
Germicides in pulp treatment, 433 
Gilded platinum, 358 

Gilling twine, use of, in polishing teeth, 182 
Gingivitis expulsiva, 505, 509 
Glands of Serres, 90 

Glossitis resulting from alveolar abscess, 501 
Gold, amalgamation of, in combination fill- 
ings, 357 
and amalgam fillings, 354 
and cement fillings, 353 



INDEX. 



847 



Gold, and platinum, 274 

and tin fillings, 365 

annealing of, 274 

as a canal filling, 463, 467 

as a filling material, 250, 267 

as a root filling, 437 

cohesive, 271 

combination fillings of, 361 

crystal, 273 
mat, 274 

device for rolling, 270 

inlays, 396 

non-cohesive, 268 
and cohesive, 363 

overlapping of, in finishing fillings, 299 

packing of, 275 

plastic, granular qualities of, 367 

plating, removal of, from steel, 365 

staining of teeth by, 558 

use of, in children's teeth, 677 
Gout, articular, 521 

nervous, 521 

tegumentary, 521 

visceral, 521 
Gouty diathesis, 519 

pericementitis, 509, 515 

theory of pyorrhea, 508, 518 
Granular layer of Tomes, 125 
Grooves, formation of, in shaping cavities, 

221 
Gubernaculum, 72 
Gum, hypersensitiveness of, 188 

incision of, for implantation of teeth, 658 

inflammatory disturbance of, 183 

lancing, indications for, 664 

protection of, in preparation of cavities, 
228 

scarification of, in pulp exposure, 416 

tissue, embryology of, 90 

treatment of, after extraction, 613 
Gutta-percha and amalgam fillings, 361 

and cement fillings, 359 

and gold fillings, 361 

as a canal filling, 463 

as a root filling, 438 
. as a separator, 187 

as a temporary filling, 214 

canal filling in bleaching operations, 545 

classes of, 326 . 

expansion of, 361 

fillings, finishing of, 334 

first use of, as a filling material, 326 

heating of, 360 

indications for employment, 327 

manipulation of, 329 

physical properties, 327 

use of, in deciduous teeth, 669 

HARLAN'S bleaching method, 551 
Harvard cement for setting inlays, 385 
Heat, evolution of, by engine burs, 218 
Hematogenic calcic pericementitis, 509 
Hemoglobin, decomposition products of, 

537 
Hemorrhage, dental, causes of, 616 

treatment of, after extraction, 614 
Hemorrhagic diathesis, treatment of, 615 



Hemostatics, formulae for, 617 
Herbst's matrices, 317 

method of inlaying, 375 

retaining method, 730 
Heredity as a predisposing cause of pyor- 
rhea, 526 

influence of, on the teeth, 690 
Hewitt's anesthetic apparatus, 624 

mouth-props, 577 
Hill's stopping, 326 
Hoe excavators, 232 

Holes, arrangement of, in rubber dam, 241 
Hollings worth's cataphoric appliances for 
bleaching teeth, 556 

syringe electrode, 206 
Hot-water douche in bleaching operations, 

548 
How's method of packing gutta-percha, 330 

of reshaping teeth, 736 
Hydrogen dioxid as a bleaching agent, 550 

in pulp treatment, 460 
Hydronaphthol, use of, in pyorrhea, 515 
Hygienic measures in pyorrhea, 529 
Hypersensitive dentin, 189 
Hypnosis, 657 

IMMEDIATE root filling, indications 
for, 431 

wedging, 185 
Implantation, first recorded operation, 646 

instruments for, 659 

mode of operation, 658 

precautions for, 654 
Impression trays for regulating, 710, 711 
Incisal cavities, filling of, 285 

preparation of, 229 
Incisions for gum-lancing, 665 
Incisor, central, extraction of, 602 
Incisors, crowded, 744 

deciduous, filling of, 675 

lateral, extraction of, 602 

macroscopical anatomy of, 22 

pulp chambers of, 446 

rotation of, 724 
Infection through instruments, 163 
Infectioso-alveolitis, 509 
Infectious alveolitis, 507 
Inflammation, treatment of, in root-filling, 

474 
Inhaler, Allis's, 213 

for nitrous oxid administration, 630 
Inlays, amalgam, 371 

antiquity of, 369 

compared with other fillings, 369 

gold, 379, 396 

hard-rubber, 399 

porcelain, 374 
Instruments, comfortable use of, 173 

disinfection of, 424 

for packing gutta-percha, 329 

for pulp-canal treatment, 452 

selection of, 276 

for. tooth extraction, 595 
Intermaxillary bone, non-development of, 

787 
Interproximal space as a predisposing cause 
of caries, 177 



848 



INDEX. 



Interproximal spaces, polishing of, 182 
Iodin, chemical action of, on hydrogen 
sulfid, 471 

trichlorid as an antiseptic, 434 
Iodoform as a germicide, 435 

gauze as a styptic, 614 

in pulp devitalization, 422 

paste, 678 
Iodol as a sterilizer, 435 
Iron, staining of teeth by, 558 

sulfid as a factor in tooth discoloration, 
538 
Irregularities, classification of, 712 

etiology of, 690 

treatment of, 702 

JACK-SCKEW regulating appliances, 
703 

Jaws, development of, 53 

separation of, for tooth extraction, 575 

KALITJM-NATKIUM, 434 
Kingsley's regulating plate, 738 
Kirk's method of making copper amalgam, 

313 
Kristaline, 343, 549 
as a cavity lining, 258 

LABAKKAQUE'S solution, 434 
as a bleaching agent, 549 
Labial cavities, filling of, 284 

preparation of, 227 
Lancets, forms of, 575 

use of, in tooth extraction, 597, 599 
Lateral walls of cavities, lining of, 258 
Laterals, depressed, 745 

extraction of, for regulating, 745 
Lead as a filling material, 267 
Leclanche battery for cataphoresis, 202 
Leeches, application of, to gum, 474 
Lenses, magnifying, for examinations, 177 
Ligatures, adjustment of, 350 
in bleaching operations, 545 
placing of, 244 
varnishing, 349 
Light, management of, in examinations, 

174 
Lingual cavities, filling of, 284, 285 
occlusion, 686 
preparation of, 227, 228 
Lining varnishes, 343 
Lithium compounds, use of, in pvorrhea, 

530 
Loop matrices, 290 
Lotion for alveolar abscess, 494 
Lugol's solution, 502 
Lysol in pulp treatment, 473, 474 

MCQTTILLEN'S bleaching method, 551 
Magnifying lenses, 175 
Mallets, first introduction of, 279 

forms of, 278 
Malocclusion, 685 

as a cause of pyorrhea, 528 
Malpighian layer, 54 
Manganese stains of teeth, 559 
Marginal cavity lining, 258 



Mass method of filling with gutta-percha, 

ool 

Massage of the gums, 184 

in pericementitis, 476 
Matrices, improvised, 316 
use of, 290 

in combination fillings, 347 
Matrix, adjustment of, to tooth, 348 
Matteson's regulating appliances, 704, 714 
Maxilla, lower, excessive development of, 

773 
Maxillse, embryology of, 53 

separation of, by regulating appliances, 
698 
Maxillary rampart, 55 

sinus, opening of, into nasal passage,, 
501 
relation of tooth roots to, 583 
Mechanical mallet, 280 
Meckel's cartilage, 54 
Medicaments, cataphoric diffusion of, 195 
Meditrina, 434 

in pulp treatment, 473 
Membrana eboris, 70, 74, 127 
Membrana praeformativa, 85 
Mercury, percentage of, in amalgams, 253, 
307 
staining of teeth bv, 559 
Mesial cavities, filling of, 287, 294 
occlusion, 686 
preparation of, 234 
Mesio-disto-incisal cavities, filling of, 288 

preparation of, 234 
Mesio-disto-occlusal cavities, preparation 

of, 238 
Mesio-incisal cavities, filling of, 288 
Mesio-labial cavities, filling of, 287 

preparation of, 233 
Mesio-lingual cavittes, filling of, 288 

preparation of, 333 
Mesio-occlusal cavities, filling of, 289 

preparation of, 235 
Metal fillings, effect of temperature on, 
352 
pulp disturbance from, 419 
Metallic fillings, insulation of, in catapho- 
resis, 203 
salts, staining of teeth by, 537 
stains, tooth discoloration by, 543 
Metals, action of chlorin on, 547 
as canal fillings, 437 
modification of alloys by, 314 
Methyl chlorid as a local anesthetic, 639 
Micro-organisms, invasion of pulp tissue 

by, 429 
Microscopic specimens, preparation of, 76 
Miller matrices, 317 

Miller's experiments on pulp mummifica- 
tion, 340 
Mineral acids, action of, on dental pulp, 

434, 436 
Mixing tablet, 339 
Modelling compound as an impression 

material, 710 
Moisture, avoidance of, in preparation of 

cavities, 219, 239, 347 
Molar, impacted, extraction of, 609, 636 



INDEX. 



849 



Molars, extraction of, 603, 607, 608 

first, early extraction of, 562 

microscopical anatomy of, 37 

pulp chambers of, 448, 449, 450, 451 

supernumerary, 48 

temporary, preservation of, 667 
Monsehs solution as a styptic, 614 
Morphia, treatment of sensitive dentin by, 

193 
Mortars for mixing amalgam, 318 
Mouth, hygiene of, 182 

mirror, use of, 175 

opener, mechanical, 576 

preliminary examination of, 173 

preparation of, for local anesthesia, 643 
Mouth-breathing, irregularities caused bv, 

566 
Mouth-props in tooth extraction, 575, 631 
Mouth-wash, antiseptic, 514 

formula for, 183 
Mucous surfaces, treatment of, preliminary 

to operation, 183 
Muffles for baking porcelain, 393 
Mummification of the dental pulp, 439 
Mummifying paste, 441, 446 

NAPKINS, use of, in filling operations, 
246 
Narcosis, symptoms of, 633 
Nasal floor, perforation of, bv alveolar ab- 
scess, 483 
Nasmyth"s membrane, 92 
Nausea, relief of, in filling operations, 247 
Necrosis from alveolar abscess, 486 
Nerve instruments, 455 
Nervous gout, 521 
" New-departure corps," 306 
Nickel, staining of teeth by, 558 
Nitrate of silver as an anesthetic, 212 
Nitric acid as an anesthetic, 212 
Nitrous oxid, advantages of, as an anesthetic, 
629 

combination of. with oxygen, 624 

in tooth extraction, 620/629 

inhaler for, 630 

mode of administration, 632 

mouthpieces for, 622 

portable apparatus, 624 
Nostrums, anesthetic, dangers of, 642 

OBTUNDING- the pulp, pressure method 
of, 425 
Occlusal cavities, filling of, 282 

preparation of, 224 
Occlusion, anterior, lack of, 786 
distal, 685 
line of. 19 
lingual. 681 
mal-, 685 
mesial, 686 
normal, 579 
Occluso-buccal cavities, filling of, 294 

preparation of, 237 
Occluso-lingual cavities, filling of, 294 

preparation of, 238 
Occupation, relation of, to. pyorrhea, 527 
Odontalgia, treatment of, in children, 666 

54 



Odontoblasts, 76, 127 

Oil of cinnamon as a sterilizer, 441 

pad, substitute for, 360 
Oils, essential, as antiseptics, 434, 436 
Operator, position of, at the chair, 173 
Oral fluids, effect of acid conditions of, 191 
Orthopedia, facial, 808 
Osmosis, influence of electrical current on, 

194 
Osteoblasts, 146 
Osteoclasts, 148 

development of, on dental pulp, 421 
Osteo-periostiti-alveolo-dentaire, 505, 509 
" Out-and-in " motion in tooth extraction, 

585, 600 
Overbite, excessive, 790 
Oxidizing bleachers, 540 
Oxvchlorid of zinc as a filling material. 
255, 334 
as a permanent filling, 548 
Oxygen as a sterilizer, 434 

combination of, with nitrous oxid, 624 
Oxysulfate of zinc, 343 
Ozena, alveolar abscess mistaken for, 483, 
487 

PACKING- of amalgam, 319 
Pain, diagnosis of, in children, 667 
Pain reflected from exposed pulps, 416 
Palladium amalgam. 313 
Paraffin as a canal filling, 464, 467 
as a root filling, 439 
coating for cement. 675 
Patients, instructions to, 182 
management of, 594 

physical examination of, before anesthe- 
sia. 618 
position of, in tooth extraction, 594 
Pepper plasters, use of. in abscess, 492 
Pericementitis, chronic, treatment of, 476 
gouty, 515 
treatment of, 473 
Pericementum, embryology of, 91 
involvement of, in pyorrhea, 522 
preservation of. in implanting teeth, 652 
revivification of. 651 
rupture of. from regulating appliances, 

701 
septic infection of. 457 
Peridental membrane, structural elements 

of, 91, 135 
Permanent teeth, indications for extraction 

of, 561 
Phagedenic pericementitis, 509 

alveolar abscess associated with, 494 
Phosphoric acid, impurities of, 337 
Phvsiognomv. relations of, to the teeth, 

805. 823 
Piano-wire regulating appliances, 703 
Pink base plate as a temporary filling, 327 
Plane, inclined, for regulating, 714 
Plastic gold, combination of, with cement, 
353 
golds, 361 
root fillings. 437 
Plastics as filling materials, 305 
Plate, regulating, 713, 721 



850 



INDEX. 



Platinum anode for cataphoresis, 205 

matrix for inlay work, 379 
Pliers, regulating, 727 
Plugging instruments, selection of, 276, 

282 
Porcelain cavity stoppers, 374 
inlavs, 374 
baking of, 393 
furnaces for baking, 393 
gold matrices for, 376, 388 
high-fusing and low-fusing tooth 

bodies for, 375, 393 
insertion of, 384 

making matrices upon models for, 400 
matching colors for, 386 
platinum matrices for, 376, 379 
preparation of cavity for, 377 
setting of, 385 
Position at the dental chair, 175 
Potassium carbonate, use of, in pvorrhea, 

530 
Poultices, use of, in alveolar abscess, 494 
Pressure method of obtunding the pulp, 425 
Profiles, study of, 810 
Prognathism, 822 
Protrusions, lower dental, 773 

upper dental, 811 
Ptyalogenic calcic pericementitis, 510 
Pulp, calcific changes in, 417 
canals, abnormalities of, 451 
cleansing of, 456 
enlargement of, 457 
filling of, in bleaching operations, 545 
septic, treatment of, 469 
sterilization of, 491 
treatment of, in deciduous teeth, 679 
capping, 411 
chambers, topographical anatomy of, 

446 
death of, from regulating appliances, 

701 
devitalization, 421 
> discoloration of tooth from death of, 536, 
539 
exposure in deciduous teeth, 677 
phenomena of, 405 
treatment of, 409 
functions of, 131 
mummification of, 429, 439 
nodules, 419 

obtunding of, pressure method, 425 
reaction of, diagnostic value of thermal 

tests to, 406 
stones, 420 

structural elements of, 127 
Pulps, mummified, in root canals, 468 
Pumice, use of, in polishing teeth, 181 
Punch, rubber dam, 241 
Pus, burrowing of, in alveolar abscess, 483, 
487 
evacuation of, in alveolar abscess, 490, 

494 
formation, results of, on tooth roots, 496 
Putrefactive decomposition, process of, 538 
Pyorrhea alveolaris, causation of, 526 
classification of, 510 
diagnosis of, 525 



Pyorrhea alveolaris, gingival origin of, 
506 
history of, 505 
pathology of, 519 
recurrence of, 531 
terminology of, 509 
treatment of, 528 
alveolo, 509 
complex, 532 

inter-alveolo-dentaire, 485, 509 
simplex, 532 
Pyrozone as a bleaching agent, 551 
use of, in alveolar abscess, 498 
in root filling, 469 

QUATERNARY amalgams, 314 

REAMERS, implantation, 555 
use of, in pulp canals, 455, 456, 461 
Records, preservation of, 416 
Regulating appliances : 

Angle's, 703, 710, 711, 727, 728, 742, 

752, 759, 769, 775, 776 
Case's, 791, 793, 834 
Coffin's, 707, 708 
Farrar's, 795 
Goddard's, 717, 719, 729, 730, 731, 732, 

767, 792 
Guilford's, 747, 751, 765 
Jackson's, 715, 752, 766 
Kingsley's, 738, 759, 789 
Magill's, 703 
Matteson's, 704, 714, 729 
Talbot's, 716, 722 
general directions for, 708 
surgical methods in, 802 
Replantation in alveolar abscess, 499 
Resin, carbolized, 667, 675 
Resistance, table of, 200 
Restoration of teeth by cemented inlays, 

369 
Retaining appliances, contact of, 702 
grooves in approximal cavities, 230, 231, 

236 
plugs, 743 
Retention caps for planted teeth, 652 
Retrusions, upper dental, 817 
Retzius, brown bands of, 107 
Rhein's method of packing amalgam, 322 
Rheostats for cataphoresis, 199 
Riggs' disease, 509 
Robinson's remedy, 207 
Root canal fillings, 463 

canals, treatment and filling of, 429 
filling in bleaching operations, 545 
Roots, anomalous, 450 
artificial, 653 
broken, removal of, 612 
depression of, by regulating appliances, 

701 
extraction of, 574 
movement of, 795 
perforation of, 503 
relation of, to maxillary sinus, 583 
resorption of, in planted teeth, 661 
Royal mineral succedaneum, 305 



INDEX. 



851 



Kubber band for regulating, 702, 706, 720, 
733 
cup for emptying abscess cavities, 493 
dam, adjustment of, 352 

for bleaching operations, 544 
application of, in children, 673 
clamps, 244, 285 

application of, 245 
holders, 245 

mode of application, 243 
punch, 241 
shields, 247 

use of, in filling operations, 239 
as a separator, 187 

SALINE waters, use of, in pyorrhea, 529 
Saliva, control of, in filling operations, 
239 
Salivary calculus, formation of, from irreg- 
ularities, 701 
removal of, 181 
Salol as a canal filling, 464, 467 
and gutta-percha canal filling, 492 
as a root filling, 439 
use of, in deciduous teeth, 680 
Sandarac varnish, 343 
Sanguinary calculus, 507 
Scalers, Abbott's, 182 
Cushing's, 512 
for root extractiou, 573 
Schleich's cocain solution, 642 
Schreier's preparation in tooth-bleaching, 

551 
Scissors, gum, 576 
Screw matrices, 292 
Secondary dentin, 414, 417 
Self-cleansing spaces, 262 
Sensitivity, zone of, in dental caries, 191 
Separations, methods of making, 185 
Separators, forms of, 186 
Septic infection of the dental pulp, 432 
Sex, relation of, to pyorrhea, 527 
Sharpey's fibers, 87 
Sheaths of Neumann, 121 
Shredded tin, use of, in root-filling, 467 
Silver nitrate, use of, in deciduous teeth, 
667 
paste, 305 
Silver-tin alloys, tables of results from an- 
nealing, 309, 310 
Simple approximal cavities, preparation of, 
229 
cavities, filling of, 282 
preparation of, 224 
Skiagraph, diagnostic uses of, 592 
Soderberg's method of pulp mummifica- 
tion, 441 
Sodium dioxid as a bleaching agent, 552 

use of, in septic pulp canals, 471 
Soft gold, 363 

and heavy gold, combination of, 364 
Space, retention of, in separations, 187 
Spheroiding of amalgams, 308 
Splints, metallic, for pyorrhea, 512 
Spring device for regulating, 722 
Stains, special bleaching methods for, 558 
Stellate reticulum of enamel organ, 64 



Sterilization of exposed pulps, 409 

of instruments by boiling in soda solu- 
tion, 169 
formaldehyd lamp for, 168 
formalin as an agent for, 167 
results of tests of various agents for, 
165 
Storage batteries, use of, for cataphoresis, 

202 
Stratum intermedium, 63 

Malpighii, 54 
Styptics for control of hemorrhage, 615 
Sulfuric acid in root canals, 456, 461 
as a sterilizer, 434 
ether, advantages of, as an anesthetic, 
212 
method of application, 212 
Sulfurous acid as a bleaching agent, 554 
Suppuration conjoint, 509 
Symbols, examination, 179 
Syringes for pulp-canal treatment, 453 
warm-air, 208 

TALBOT'S regulating appliances, 716, 
722 
Tampon for controlling hemorrhage, 614 
Tannic acid in pulp exposure, 679 
in pulp treatment, 422 
use of, in hemorrhage, 614 
Tap openings for pulp treatment, 459 
Tape as a separator, 186 
Tartarlithine, lithium bitartrate, 530 
Taylor's regulating appliance, 751 
Teeth, abnormalities in, 593 

accidents to, during extraction, 612 
anchorage of, in regulating, 715 
bleaching of, 540 
Carabelli's sectional views of, 442 
cleansing of, 181 
crowded, extraction of, 613 
deciduous, alveolar abscess in, 680 
duration of, 665 
eruption of, 663 
extraction of, 595, 600 
filling of, 669 

macroscopic anatomy of, 48 
prophylactic treatment of, 681 
pulp treatment of, 677 
rules agains-t extraction of, 691 
discoloration of, 535 
by amalgam, 358 
embryology of, 53 
examination of, preliminary to operation, 

173 
exfoliation of, in pyorrhea, 518 
extraction of, 561 
for regulating, 746 
under anesthesia, 634 
extrusion of, 729 
forces used in moving, 708 
histology of, with reference to operative 

dentistry, 93 
immediate movement of, 799 
indications for extraction of, 561 
influence of, on the phvsiognomv, 805, 

823 
instruments for extraction of, 564 



852 



INDEX. 



Teeth, irregularities of, 690 
labial displacement of, 720 
lingual displacement of, 712 
lower, extraction of, 606 
macroscopic anatomy of, 17 
movement of, in regulating, 709, 718 
normal forms of, 592 

occlusion of, 19, 684 
oral, combination fillings for, 353, 355 

extraction of, 606 
partial eruption of, 731 
parts of, most liable to caries, 177 
permanent, order of eruption, 688 
plantation of, 645 
planted, life of, 654 

mode of attachment, 653 
subsequent care of, 652 
pulp chambers of, 446 
relation of, to temperament, 51 
removal of, for artificial dentures, 563 
replantation of, 648 

in alveolar abscess, 499 
reshaping of, 736 
retention of, after regulating, 742 
rotation of, 724 

in extracting, 600 
scaling of, in pyorrhea, 512 
separation of, 185, 243 
surgical anatomy of, 577 
temporary, abscess on, 502 
combination filling for, 359 
indications for extraction of, 561 
management of, 663 
temperature sense of, 402 
transplantation of, 650 
upper, protrusion, 760, 773 
Tegumentary gout, 521 
Temperament, relation of teeth to, 51 
Temperamental indications for pulp treat- 
ment, 415 
Temperature sense of teeth, 402 
Temporary stopping, 342, 438 
Ternary amalgams, 313 
Therapeutic treatment of sensitive dentin, 

193 
Therapeutics of pulp treatment, 433 
Thermoscopic heater, 331 
Thumb-sucking, irregularities caused by, 
696^ 
relation of, to protruding teeth, 761 
Tin, as a canal filling, 463 
as a cavitv lining, 258 
as a filling material, 251, 267, 295 
cohesive property of, 296 
felt. 296 

instruments for filling with, 296 
shavings of, 296 
shredded, 296 

thermal conductivity of, 251 
use of, in children's teeth, 677 
Tin-gold, 365 



Tin and gold, 367 

Tissues, changes of, by movement of teeth, 
697 

Tomes, fibers of, 127 
granular layer of, 125 

Tonics, general, 616 

Tonsils, enlarged, irregularities caused by, 
697 

Tooth development, chronology of, 88 
extraction, general principles in, 593 
forms, evolution of, 17 

variations of, 50 
molar, impaction of, 589 
preparation of, for bleaching, 543 
structure, discoloration of, by amalgam, 
311 
saving of, by combination filling, 356 

Toothache, treatment of, in children, 666 

Tooth-brush, correct use of, 182 

Townsend's alloy, 313 

Transillumination of the teeth, 177 

Transmission of oral diseases, 160 

Trichloracetic acid, use of, in pyorrhea v 512 

Tropacocain as a local anesthetic, 642 

Truman's bleaching method, 546 

Tuberculate teeth, 37 

Tutt's powder, 182 

U KATES, accumulation of, in the blood, 
521 
Uric acid theory of pyorrhea, 508 

VARNISHING fillings, 333 
Velvet gold cylinders, 289 
Veratria, treatment of sensitive dentin by, 

193 
Visceral gout, 521 
Vulnerable point of cavities, 235 

WATERING of amalgams, 320 
"Warmed air as an anesthetic, 207 
Wedges for regulating, 718 
as separators, 185 
use of, in examinations, 177 
Weston's method of mixing cements, 339 
Willms controller for cataphoresis, 202 
Wright's bleaching method, 549 

ZINC chlorid as an anesthetic, 209 
use of, in root canals, 462 
oxychlorid as a canal filling, 463 
as a root filling, 437 
formula of manufacture, 336 
use of, in dentistry, 336 
oxysulfate as a pulp capping, 343 
phosphate as a cavitv lining, 259 

as a filling material, 256, 267, 338, 346, 

672 
cements, 336 
making of powder, 336 
mixing of, 339 



